Speech and language therapy to improve the communication skills of children with cerebral palsy (Review)

Transcription

1 Speech and language therapy to improve the communication skills of children with cerebral palsy (Review) Pennington L, Goldbart J, Marshall J This is a reprint of a Cochrane review, prepared and maintained by The Cochrane Collaboration and published in The Cochrane Library 2005, Issue 4 1

2 T A B L E O F C O N T E N T S ABSTRACT SYNOPSIS BACKGROUND OBJECTIVES CRITERIA FOR CONSIDERING STUDIES FOR THIS REVIEW SEARCH STRATEGY FOR IDENTIFICATION OF STUDIES METHODS OF THE REVIEW DESCRIPTION OF STUDIES METHODOLOGICAL QUALITY RESULTS DISCUSSION AUTHORS CONCLUSIONS POTENTIAL CONFLICT OF INTEREST ACKNOWLEDGEMENTS SOURCES OF SUPPORT REFERENCES TABLES Characteristics of included studies Characteristics of excluded studies ADDITIONAL TABLES Table 01. Methodological quality of group studies Table 02. Methodological quality of single case studies Table 03. Summary of results for single case experimental designs GRAPHS AND OTHER TABLES INDEX TERMS COVER SHEET i

3 Speech and language therapy to improve the communication skills of children with cerebral palsy (Review) Pennington L, Goldbart J, Marshall J This record should be cited as: Pennington L, Goldbart J, Marshall J. Speech and language therapy to improve the communication skills of children with cerebral palsy. The Cochrane Database of Systematic Reviews 2003, Issue 3. Art. No.: CD pub2. DOI: / CD pub2. This version first published online: 21 July 2003 in Issue 3, Date of most recent substantive amendment: 27 March 2003 A B S T R A C T Background The production of speech, language and gesture for communication is often affected by cerebral palsy. Communication difficulties associated with cerebral palsy can be multifactorial, arising from motor, intellectual and / or sensory impairments, and children with this diagnosis can experience mild to severe difficulties in expressing themselves. They are often referred to speech and language therapy (SLT) services, to maximise their communication skills and help them to take an independent a role as possible in interaction. This can include introducing augmentative and alternative communication (AAC) systems, such as symbol charts or speech synthesizers, as well treating children s natural forms of communication. Various strategies have been used to treat the communication disorders associated with cerebral palsy but evidence of their effectiveness is limited. Objectives To determine the effectiveness of SLT that focuses on the child or their familiar communication partners, as measured by change in interaction patterns. To determine if individual types of SLT intervention are more effective than others in changing interaction patterns. Search strategy Searches were conducted of MEDLINE, CINAHL, EMBASE, PSYCH INFO, LLBA, ERIC, WEB of SCIENCE, NRR, BEI, SIGLE up to December References from identified studies were examined and relevant journals and conference reports were handsearched. Selection criteria Any experimental study containing an element of control was included in this review. This includes non-randomised group studies and single case experimental designs in which two interventions were compared or two communication processes were examined. Data collection and analysis L Pennington searched for and selected studies for inclusion. J Goldbart and J Marshall independently assessed separate random samples each comprising 25% of all identified studies. Two reviewers independently abstracted data from each selected study. Disagreements were settled by discussion between the three reviewers. Main results Eleven studies were included in the review. Seven studies evaluated treatment given directly to children, four investigated the effects of training for communication partners. Subjects in the studies varied widely in age, type and severity of cerebral palsy, cognitive and linguistic skills. Studies focusing directly on children suggest that this model of therapy delivery has been associated with increases in treated communication skills by individual children. However, methodological flaws prevent firm conclusions being made about the effectiveness of therapy. In addition, maintenance of these skills was not investigated thoroughly. The studies targeting communication partners describe small exploratory group projects which contain insufficient detail to allow replication, have very low power and cannot provide evidence of effectiveness of this type of treatment. 1

4 Authors conclusions Firm evidence of the positive effects of SLT for children with cerebral palsy has not been demonstrated by this review. However, positive trends in communication change were shown. No change in practice is recommended from this review. Further research is needed to describe this client group, and its possible clinical subgroups, and the methods of treatment currently used in SLT. Research is also needed to investigate the effectiveness of new and established interventions and their acceptability to families. Rigour in research practice needs to be extended to enable firm associations between therapy and communication change to be made. S Y N O P S I S Speech and language therapy for children with cerebral palsy might improve their communication skills, but more research is needed. Cerebral palsy (CP) is a movement disorder caused by damage to the brain before, during or soon after birth. The ability for people with CP to communicate effectively is often impaired by problems with speech and gestures usually used in communication. Speech and language therapy aims to help people with CP maximise their communication skills. This can include ways of enhancing natural forms of communication, introducing aids such as symbol charts or speech synthesisers, and training communication partners. The review found some weak evidence that speech and language therapy might help children with CP, but more research is needed. B A C K G R O U N D Cerebral palsy is a persistent disorder of movement and posture caused by non-progressive pathological processes of the immature brain ( Aicardi 1992). Subgroups of cerebral palsy have been classified according to clinical signs: spastic, ataxic and dyskinetic syndromes, plus mixed forms (Hagberg 1989). Speech disorders are associated with each clinical subgroup, and affect children s speech intelligibility. The prevalence of cerebral palsy is approximately 2.5 per 1000 live births in countries with neonatal intensive care facilities (Colver 2000, Hagberg 1996, Pharoah 1996, Stanley 1992). Rates have risen in infants weighing < 2499g, and continue to rise in infants of extremely low birth weight/prematurity (<1000g, <28 weeks), due to increasing perinatal survival (Colver 2000). Speech disorders can be associated with any type of cerebral palsy. However, prevalence figures have not been reliably calculated to date. The Western Australian Cerebral Palsy Register recorded 21.4% of children born as non-verbal, i.e. unable to produce intelligible speech (Watson 1999). Additional children would have less severe speech disorders that may require speech therapy intervention, but these cases were not recorded. Children with cerebral palsy can also experience difficulties in other areas of communication, such as the development of reliable gesture and facial expression, the acquisition of receptive and expressive language, and voice production. However, prevalence of these disorders has not been established. Children may experience communication difficulties from early infancy and, as cerebral palsy is a persistent condition, communication impairments are chronic and children may require long term intervention. In a review of speech and language therapy caseloads in the UK Enderby 1986 estimated that cerebral palsy was the sixth most common medical cause of speech disorder, and the proportion of referrals of children with this diagnosis remains static (Petheram 2001) Speech and language therapists (also known as speech therapists, speech-language pathologists) assess, diagnose and treat the communication disorders associated with cerebral palsy. The aim of treatment is to maximise children s ability to communicate, through speech, gesture and/or supplementary means such as communication aids, to enable them to become independent communicators. As the problems experienced by children with a diagnosis of cerebral palsy are wide in range there is no single universally appropriate form of treatment. Intervention can focus directly on spoken output, expressive or receptive language development, or helping children to develop conversation skills such as asking questions and repairing conversation when misunderstandings occur (e.g.letto 1994). Work to develop children s language or communication skills could involve children using any method of communication. Intervention can also involve children s familiar conversation partners, such as their families, friends and teaching staff (Culp 1988, Pennington 1996). Such indirect therapy aims to teach people who are in close contact with children with cerebral palsy to facilitate their communication development by creating opportunities for them to use new skills in conversation. Effective indirect intervention would lead to changes in conversation style for both the familiar conversation partners and the children. Speech and language therapy may be delivered in a range of settings, including clients homes, community clinics, hospitals and schools (RCSLT 1999). It is usual for speech and language therapists to liaise with families and teaching staff regarding therapy, to ensure that intervention goals are incorporated into daily life where possible (Calculator 1991). Therapy may be delivered on an individual basis or in groups. Intervention may also vary in duration and intensity. 2

5 Speech and language therapy for this group of children is often long term, requiring significant health service resources. Recently, the effectiveness of speech and language therapy has been called into question (Enderby 1997). For this client group it is necessary to know if changes that occur in children s communication are a result of SLT intervention or other factors, such as maturation. If it is demonstrated that speech and language therapy is effective, information about the effectiveness of different kinds or components of therapy, for children from different clinical subgroups, is needed to ensure appropriate use of resources. Aim To conduct an exploratory systematic review of studies of speech and language therapy for children who have communication disorders associated with cerebral palsy. This initial, broad review will investigate the forms of SLT currently used to remediate different types and severities of communication disorders associated with cerebral palsy, and their relative effectiveness, with a view to providing directions for future research. O B J E C T I V E S 1 To assess whether direct intervention aimed at improving the communication skills of children with cerebral palsy is more effective than no intervention at all. 2 To assess whether individual types of intervention are more effective than others in improving the communication skills of children with cerebral palsy. 3 To assess whether intervention aimed at changing the conversational style of the familiar communication partners of children with cerebral palsy is more effective than no intervention at all: (i) in changing partners conversational style and (ii) developing communication skills of children with cerebral palsy. 4 To assess whether one particular type of intervention is more effective than others in changing the conversation style of the familiar communication partners of children with cerebral palsy. C R I T E R I A F O R C O N S I D E R I N G S T U D I E S F O R T H I S R E V I E W Types of studies Any controlled study of interventions aimed at improving communication skills, reported in any language; translations were sought when necessary. Types of participants Any child under 20 years of age with any communication disorder associated with cerebral palsy, including dysarthria, dyspraxia, ataxia and mixed syndromes, or their communication partners. No exclusions were made on the basis of additional impairments (intellectual or sensory impairments, the presence of epilepsy) or prior receipt of speech and language therapy. This age range was selected as people who have identified special needs are entitled to statutory education provision up to 19 years of age in England, which could specify speech and language therapy. Types of intervention Any therapy aimed at improving communication skills, whether provided individually or in groups, or in the child s home, school or health service settings, except where it is provided as part of a holistic approach (for example, as in conductive education). 1. Therapies given directly to the child with the aim of developing the child s communication skills are distinguished from 2. Therapies given to familiar communication partners (families, teachers, teaching assistants, peers) with the aim of changing the communication partner s conversation style to help them facilitate children s communication development. Types of outcome measures 1. Measures of communication: a) children s expressive and receptive language skills, speech production, conversation/pragmatic skills, intelligibility, communicative competence; b) partners communication and interaction strategies Measures used may be, for example: rating scales, language tests, coding schemes developed for individual research studies that include validity and reliability data. 2. Family stress and coping (e.g. Questionnaire on Resources and Stress, Carer Strain Index) 3. Satisfaction of patient and family with treatment 4. Non-compliance with treatment S E A R C H S T R A T E G Y F O R I D E N T I F I C A T I O N O F S T U D I E S See: Movement Disorders Group search strategy 1. The review is based on the search strategy of the Movement Disorders Group and a more general search strategy: a. cerebral palsy AND child b. speech OR speech disorder OR speech intelligibility OR speech therapy OR speech and language therapy c. language OR language disorders OR language development disorders OR sign language OR child language OR language therapy d. communication OR communication aids for disabled OR communication disorders OR communication methods, total OR manual communication OR nonverbal communication e. #b OR #c OR #d f. a AND e 3

6 The following electronic data bases were searched up until December 2002: MEDLINE (from 1966); CINAHL (from 1982); EMBASE (from 1980); Psych Info(from 1967); Web of Science (from 1981); Language and Linguistic Behaviour Abstracts (from 1973); British Education Index (from 1986); National Research Register (completed and ongoing research); ERIC (from 1966); Aslib Index to UK theses (from 1970); SIGLE (from 1980). 2. The following journals were hand-searched from their inception or from 1980 onwards: International Journal of Language and Communication Disorders, Augmentative and Alternative Communication, Child Language Teaching and Therapy, Developmental Medicine and Child Neurology, Child: Care, Health and Development and the Ambulatory Child, Journal of Child Psychology and Psychiatry and Allied Disciplines, Topics in Language Disorders, European Journal of Special Needs Education, Journal of Communication Disorders, Journal of Psycholinguistic Research, Journal of Special Education, International Journal of Rehabilitation Research, Folia Phoniatrica et Logopaedica, Applied Psycholinguistic Research, Journal of Speech, Language and Hearing Research, Australian Journal of Communication Disorders, American Journal of Speech-Language Pathology, International Journal of Disability, Development and Education, Speech, Language and Hearing in Schools. (The current titles are given for journals experiencing name changes since 1980) 3. Published conference proceedings of the following organisations were checked: European Academy of Child Development ( ), International Society for Alternative and Augmentative Communication ( ), American Speech and Hearing Association ( ), Royal College of Speech and Language Therapists ( ). 4. Reference list of all studies selected for possible inclusion were checked for other possible eligible studies. 5. Authors of included trials were contacted for unpublished studies. Calls for assistance were made via national professional associations. M E T H O D S O F T H E R E V I E W One reviewer (LP) assessed the studies identified by the search strategies for inclusion according to specified criteria. The other two authors independently assessed separate random samples each comprising 25% of all identified studies plus any studies whose inclusion status was ambiguous. Agreement on inclusion was calculated using the Kappa statistic. The opinion of the third reviewer was sought if there was any disagreement regarding the inclusion of a trial. Two reviewers reviewed each identified study, abstracted data using forms developed for the review and graded the study s methodological quality. Where necessary author/s were contacted at their last known address to provide missing data for included trials. Attention was paid to whether studies demonstrated protection from the following types of bias: selection bias, i.e. true random sequencing, true concealment up to the time of allocation, comparison of known confounding variables between groups, comparison of developmentally similar processes in single case experimental designs performance bias, i.e. differences in types of treatment (cointerventions) between the two groups exclusion bias, i.e. withdrawal after entry to the trial detection bias, i.e. unmasked assessment of outcome. The methodological quality of single case experimental designs was also rated on the description of the subject and intervention, whether baseline performance was adequately established, the duration of treatment and follow-up and the frequency of measurement across the phases of the experiment. Individual criteria were rated as met, unmet or unclear. Disagreements were resolved with a third reviewer. Agreement on methodology assessment was calculated using the Kappa statistic. Data from studies meeting criteria for inclusion were entered into RevMan. Most studies included used single case experimental designs. Four group trials were identified, but only one included randomisation and the subjects were heterogeneous. Data were therefore not combined for the review. D E S C R I P T I O N O F S T U D I E S Searches yielded 832 abstracts. 737 clearly did not fit the inclusion criteria for the review. Full texts of 95 papers were considered for potential inclusion. Authors agreed on 45 of the 48 papers randomly selected for reliability check, K = Disagreements were resolved with a third reviewer for the other papers. Twelve papers were included for full review. The main reasons for exclusion were that subjects included did not have cerebral palsy or those with cerebral palsy could not be disaggregated from other subjects, or the study did not include any experimental control. Most reports were written in English. Papers in other languages were read by translators who discussed the content with reviewers; none were found to fit the inclusion criteria for the review. THERAPY FOCUSING ON CHILDREN Seven of the included studies evaluated therapy that focused directly on children, who varied widely in age, type and severity of cerebral palsy and additional impairments. These studies aimed to facilitate the development of pre-intentional communication skills (behaviours such as mutual gaze, anticipation of behaviours in familiar routines that can be interpreted as communication by others, but which are not preformed with the intention of conveying a message), pragmatic / communicative functions used in 4

7 conversation, such as asking questions, providing information or repairing misunderstandings, or expressive language structures. Pre-intentional communication Richman 1977 used operant teaching strategies to train a nine year old girl with severe cognitive impairment, who lived in an institution, to produce three pre-intentional communication skills: maintaining eye contact and head control and increasing vocal imitations. Forty hours of therapy were given over 20 weeks. Ten minute intervals were sampled for the presence of the three behaviours. Communicative functions In five studies children were taught to use individual communicative functions. In three of these, Hunt 1986, Pinder 1995 and Sigafoos 1995 taught children to use requests for objects or actions. Hunt 1986 included one seven year old girl with cerebral palsy who had severe cognitive impairment and multiple disabilities in a multiple probe multiple baseline across subjects design. Other subjects did not have cerebral palsy. The subject was taught to request four objects or events by eye pointing to line drawings symbolising the object or action. Operant teaching methods were used, including interrupted chain training. Treatment was given twice daily, with 55 sessions in total. Requests were probed across the treatment sessions. Pinder 1995 taught 4 infants with cerebral palsy to produce either requests for objects or requests for more of an activity using micro teaching techniques (creating a communication environment, modeling the target skill, expectant delay, prompting and reinforcement). The children were aged months, had severe cerebral palsy with no independent sitting and less than 50 on the Mental Development Index. Therapy was given twice a week for up to twelve weeks. Taught and untaught requests were probed in the teaching situation and across a second familiar communication situation. Sigafoos 1995 reported the training of a six year old boy with severe cerebral palsy and moderate cognitive impairment to request three items using micro teaching strategies, requests were probed throughout treatment. Three sessions were given per week, with 19 sessions in total. In the fourth, Davis 1998 taught two children to produce responses to statements made by others in conversation. One of the subjects was a 15 year old boy with severe cerebral palsy who usually communicated by yes/no responses only but who had access to a voice output communication device with pre-stored phrases and spelling for novel words. Communication partners provided structured opportunities for the boy to respond to statements in conversation with further information that maintained the interaction. These elicitations were added to the conversation of three partners in succession. Responses to statements were recorded across the treatment sessions with the three partners. Therapy was given 2-3 times per week, 36 sessions in total. In the fifth, Hurlbut 1982 trained three teenage boys with severe cerebral palsy and cognitive impairments to label objects using Blissymbols or iconic line drawings using micro teaching strategies. The duration and frequency of therapy sessions was not stated. The proportion of Blissymbols and iconic symbols used to label taught and untaught items was calculated before and throughout training. Expressive language Campbell 1982 used operant training techniques to teach a 10 year old boy with severe cerebral palsy and moderate language delay to produce is / are in three linguistic structures. Two 15 minute therapy sessions were given each day, with 155 sessions in total. Frequency of correct is / are production in each of the three target structures was measured during each training session. THERAPY FOCUSING ON PARENTS OR OTHER CON- VERSATION PARTNERS Five studies investigated the success of training communication partners to facilitate the communication development of children with cerebral palsy (Basil 1992, Hanzlik 1989, McCollum 1984, McConachie 1997, Pennington 1996a). In all but one study (Mc- Collum 1984) trained communication partners were compared with partners who received no training. Pennington 1996a reports the same information, but in different format, as McConachie 1997, and will be excluded from further discussion. Participants Children Children whose parents and educators received training in the four studies appear heterogeneous. However, insufficient information is given to provide a clear picture of the their overall level of functioning. They ranged from 8 months of age to 17 years, had cerebral palsy classed as mild to severe and cognitive skills ranging from within normal limits to severely impaired. Hanzlik 1989 included 20 infants aged 8 to 32 months, who had cerebral palsy of different types and severity ranging from mild to severe. Mental age was at least one standard deviation below the mean, range 2-18 months. None of the infants were able to ambulate either independently or with aids. Some, although it is difficult to tell how many, fell into the category containing speech impairment. However, some of those children may not have been expected to communicate intentionally given their chronological and mental age. Levels of communication development were not specified. McCollum 1984 included one child with severe cerebral palsy, of unknown type, aged 18 months. He was reported to vocalise but to exhibit few social behaviours. No other information is given regarding his developmental level. Basil 1992 studied four Spanish children aged 7-8 years who had cerebral palsy of unstated type. They had no independent mobility and upper limb function was severely affected. One child scored 4.5 years on a test of mental development, the others did not reach baseline. These children communicated by vocalisation, eye gaze, facial expression and produced one symbol messages on their communication boards, which contained symbols. McConachie 1997 included 9 children aged 7-17 years who had cerebral palsy of differing types. No information was given on the severity of their motor impair- 5

8 ments, cognitive or sensory skills. All had symbol communication systems (6 used Blissymbolics, 3 Rebus Symbols), with access to symbols. Two children also had voice output communication aids. No information is given about how the children used their communication systems or their communicative level. Adult conversation partners With the exception of McConachie 1997, who trained teachers and education assistants, parents were the subjects of the research. Overall, very little information is provided on the people who were trained, their communication style before intervention, previous training and relationship with the subject children. None of the studies includes information on parental stress and coping, which has been found to affect communication (Dunst 1988). Basil 1992 trained 3 mothers and one father. They were compared with teachers who received no training. No information was given on prior training or other characteristics of either group other than the pre-intervention interaction measures which showed different communication styles between the two groups. The mothers who participated in Hanzlik 1989 had completed varying levels of education, from partial high school to college graduation. Half of the families in each group had other children. The employment of parents ranged from major professionals to semi-skilled workers. However, it is not clear if any of the mothers were employed outside the home or how social status was classified. The mother in McCollum 1984 was a single parent with a lower-middle income, no other information was given. McConachie 1997 included 9 teachers and 10 assistants in the experimental group who received training and 8 teachers and 6 assistants who received no intervention. No other information was given on the adult subjects, who volunteered to take part and who were assigned by their managers to the two groups. Authors stated that the participants and controls were matched on gender and extent of interaction with the subject children, however no supporting evidence is presented in the paper. Intervention The training given all related to facilitating communication development. McCollum 1984 and Hanzlik 1989 both concentrated on preverbal communication. McCollum 1984 provided direct teaching of target skills specific to the parent and child receiving therapy. 10 weekly home visits were made, in which target behaviours were watched on video-tape and practiced and treated and untreated communication behaviours measured. Hanzlik 1989 gave a generic model of training to each mother, focussing either on interaction and the use of adaptive seating for the experimental group, or neurodevelopmental therapy for the control group. Training in this study was given at home in one session that lasted one hour. Basil 1992 and McConachie 1997 both undertook group teaching to facilitate interaction with individual AAC users. Basil 1992 trained a group of parents in one session then followed this training up with three home visits to each family to individualise intervention and help parents practice techniques. McConachie 1997 trained teachers and assistants in their own school in five 90 minute workshop sessions which concentrated on one child. Both Basil 1992 and McConachie 1997 used short talks, brainstorming and videotapes in their group teaching. Outcome measures Each study used outcome measures developed specifically for the research project, which related to the specific aims of the therapy. Only one (Hunt 1986) had information on validation. Inter-rater reliability of use of the coding schemes was given in each paper. M E T H O D O L O G I C A L Q U A L I T Y See Table 01and Table 02 for ratings of the methodological quality of included studies. It is rarely possible or advisable to blind patients and clinicians to the type and aims of intervention in trials of speech and language therapy, but this does leave them open to performance and attrition bias. GROUP STUDIES (Basil 1992, Hanzlik 1989, McConachie 1997) 1. Randomisation and concealment of allocation Basil 1992 and McConachie 1997 did not randomly assign subjects to treatment or control groups. Basil 1992 gave training to parents and compared their communication with that of teachers who received no training. Teachers and assistants who participated in the McConachie 1997 study were assigned to treatment and control group by their school managers on the basis of school timetable, as staff were released to participate in training workshops. Allocation was not concealed as the person(s) who allocated subjects also decided on their eligibility. Both of the studies, therefore, have significant weakness in their allocation strategies and selection bias is likely. Hanzlik 1989 recruited parents through colleagues. Parents who were willing to take part in the study were allocated to group as they were recruited by the investigator by her taking a piece of folded paper out of a bag. 20 papers were created, 10 consigned parents to control and 10 to experimental group. 2. Similarity of subjects at baseline Information on recruitment to the studies is not provided for Basil 1992 and McConachie 1997, nor are inclusion and exclusion criteria cited. For Basil 1992 subjects and controls differed in their relationship to the children; parents received training, teachers were controls and received no training. The two groups clearly differed in their pre-intervention patterns of interaction. No information was provided on other possible confounding variables such as previous training in communicating with children who use AAC, beliefs about interaction, age, education, socio-economic status, and extent of knowledge and experience of AAC. This study is rated as inadequate on subject similarity. Subjects and controls in Mc- Conachie 1997 were matched on gender, occupation and extent of contact with the target children by managers. Pre-intervention communication ratings and information on possible confounders 6

9 such as those listed above were not given. Therefore, is not possible to detect how similar the two groups were before training. Hanzlik 1989 provides sufficient information on subjects to assess the similarity of the groups and to replicate the research with similar samples. She cited inclusion criteria that related to children s locomotor, cognitive and sensory skills and excluded mothers who had received previous training in either of the intervention strategies used in the study. The gender, type and severity of cerebral palsy, extent of locomotor skills, chronological and mental age is given for the children in each group in terms of frequencies, means and SDs, with groups seeming to be equally matched. Mothers were similar across groups in education and half of those in each group had other children. The range of SES of the households of the two groups was slightly wider for the control group, and the numbers of subject families in each SES group is not given. Pre-intervention scores (means and SDs) for interaction behaviours are given for the mothers and infants in both groups and appear similar. 3. Subject numbers None of the studies provided information how the number of subjects was chosen. Number of subjects ranged from 8 (Basil 1992) to 20 (Hanzlik 1989). With such small numbers of subjects it is unlikely that the sample can reflect the population of people who regularly converse with children who have cerebral palsy. The studies also have very low chances of detecting a true effect of training. 4. Blinding Appropriately for therapies involving training and subject co-operation, none of the studies included the blinding of the subjects or of the clinicians providing therapy. However, the outcomes of the interventions were inappropriately assessed by the clinicians providing the therapy, which increases the risk of detection bias. Bias was reduced, but not eliminated by the inclusion of a reliability check of coding with a blind assessor. Basil 1992 checked a nonrandom sample of 12.5% sessions from before, during and after therapy, with agreement 90, 92, 98%. Hanzlik 1989 reported K = agreement from data from each of the children, across 14 categories but did not state the amount of data on which this was calculated. In McConachie 1997 half of the data were coded by the second author, half by a blind assessor, with agreement calculated as 76% (71-79%) on 15% of the total data. As only small proportions of data were included in the reliability checks, each of the studies is still open to detection bias. 5. Description of the intervention From the information given in the studies it would not be possible to replicate the intervention provided by Basil It is also unclear how similar the intervention was between subjects within the groups. McConachie 1997 provided fuller description of the intervention and the training programme used has been published ( Pennington 1993), allowing replication. Hanzlik 1989 provided additional information on the treatment protocols, which would allow partial replication. 6. Analysis Data were analysed in the category to which subjects were originally allocated. No cross-over was reported or could be detected in any of the three group studies. Basil 1992 and Hanzlik 1989 analysed data from the very small numbers of subjects as groups, using parametric tests, which are unsuitable for such a small sample size. McConachie 1997 used appropriate statistical tests. Hanzlik 1989 measured 14 variables from the samples of interaction, and Basil 1992 measured 10, increasing the likelihood of obtaining a statistically significant result by chance. However, this was not taken into account in the authors conclusions. Loss to follow-up occurred only in McConachie 1997, where a high attrition rate was observed, especially for the control group. The attrition is unexplained and leaves the study open to attrition bias. SINGLE CASE STUDIES 1. Subject description For replication of single case studies and moving from hypothesis generation to hypothesis testing subjects need to be described in detail. All of the studies included in the review gave the subject child s chronological age and most gave a rating of their severity of cerebral palsy (mild, moderate, severe). Some gave children s type of cerebral palsy and rated the severity of any additional cognitive impairments. Few gave information on sensory impairments (Pinder 1995 only) and epilepsy or details of children s receptive language development. Most cited children s present modes of communication and gave a very brief overview of their use of their communication skills in interaction. However, none of the studies included in the review gave sufficient detail to select with certainty other subjects with a similar type of cerebral palsy, level of locomotor skills, cognitive and communication development. Davis 1998, Hunt 1986, Hurlbut 1982, Pinder 1995 were judged to give a partial account of children s level of functioning. The description given by Campbell 1982, McCollum 1984, Richman 1977 and Sigafoos 1995 were judged to be inadequate for replicating the study. 2. Equality of skills assigned to treatment and control To avoid selection bias and the effect of maturation, targeted skills need to be of similar developmental level and prognostic indication and assigned at random to treatment or control / later treatment in multiple baseline designs. Richman 1977 compared communication skills with a motor skill. Pinder 1995 and Sigafoos 1995 selected target skills that were very similar, and which may have been expected to generalise for the included subjects. Therefore, an increase in control skill as well as treated skill would be expected. The other studies investigated skills of similar prognostic indication and were rated adequate in skill selection. However, none of the studies stated if skills were assigned to treatment (or a place in a sequence of treatments for multiple baseline across processes designs) or control randomly, which could introduce selection bias. All studies were rated as unclear on this criterion. 3. Description of the intervention 7

10 For single case studies to be replicated, interventions, which are often new in these designs, need to be described in detail. Davis 1998, Richman 1977 and Sigafoos 1995 were judged to describe the intervention in sufficient detail for it to be replicated. Campbell 1982, Hunt 1986, Hurlbut 1982, McCollum 1984 and Pinder 1995 were judged to give only part of the information needed to replicate intervention. Information was usually provided on the frequency and duration of treatment but was lacking on the exact methods of eliciting skills from individual children. For example, in which communication situations skills were elicited, when in an activity communication opportunities were provided and the methods used to teach a communication strategy to a mother. 4. Blinding None of the studies included blinding subjects or clinicians to the aims or type of therapy. In all studies data on outcome measures were collected by the investigators, but included checks on the reliability of coding using a second observer, which could reduce detection bias. All studies except McCollum 1984 used data collected from the subjects during the study. Amount of data checked ranged from 17-50%, only that used by Pinder 1995 was selected randomly. Most studies calculated agreement using percentage (agreement-disagreements/total number of behaviours coded), which does not adjust for chance agreement. Agreement ranged from %. Pinder 1995 calculated agreement using Kappa, achieving more than K = 0.60 for each subject. Taking into account the amount of data checked, the selection method used and the agreement achieved Pinder 1995 and Davis 1998 were judged to partially meet the blinding criterion. Campbell 1982, Hunt 1986, Hurlbut 1982, McCollum 1984, Richman 1977 and Sigafoos 1995 were judged inadequate and to be at considerable risk of detection bias. 5. Duration of phases and measurement To show that intervention leads to change in single case experiments, frequent measurements should be taken in baseline, intervention and follow-up/maintenance phases, and phases should be of similar duration. Without the use of randomisation tests (Edgington 1995), baseline should be adequately established with a plateau across at least three measurements or with a downward trend. If treatment is successful a clear upward trend should be observed during the intervention phase. In studies aiming for the acquisition of new skills the behaviour should continue at similar levels to the intervention phase in follow-up/maintenance with no intervention. Campbell 1982, Davis 1998, Hurlbut 1982, Pinder 1995 and Richman 1977 showed baselines that were adequate, with demonstration of stable behaviours. Hunt 1986, McCollum 1984 and Sigafoos 1995 did not demonstrate stable behaviour at baseline and are rated inadequate. The intervention in Campbell 1982, Hunt 1986 and Hurlbut 1982 shows a clear upward trend in target behaviour. Similar changes are partially demonstrated by Pinder 1995 and Davis 1998 with higher scores than baseline but variability. In Sigafoos 1995 scores are higher in intervention but reduced at the end of treatment, which should have been continued to investigate a possible downward trend. No clear trends are demonstrated by McCollum 1984 or Richman 1977 with lots of variation in the scores. The follow-up phases of all studies are rated as inadequate due to their absence, short duration or change in target behaviours. Measurements of all target skills were taken continuously across phases by Campbell 1982, Pinder 1995 and Richman Data across sessions were aggregated by Davis 1998, taken infrequently for control behaviours by Hunt 1986 and presented as means by Hurlbut 1982; partially meeting the criterion relating to measurement. McCollum 1984 and Sigafoos 1995 included one measurement only for follow-up and Sigafoos 1995 measured control processes at baseline and follow-up only. 6. Confounding variables None of the studies discussed confounding variables and all were rated unclear on this criterion. It is possible that for Sigafoos 1995 and Pinder 1995 the control skill was too similar to the treated skill and would be expected to generalise without treatment for the subjects. 7. Analysis Statistical tests have been developed for single case experimental designs (Edgington 1995). However they have not been widely used and none of the studies included in the review employed statistical analysis. Analysis involved visual inspection of the graphed data and subjective interpretation. 8. Replication Pinder 1995 included four preverbal infants, Hurlbut 1982 included three teenagers with severe cerebral palsy and cognitive iimpairment Subjects appeared similar in prognostic indication. Other studies included in the review did not systematically replicate their interventions to other children with cerebral palsy. Some included children with other medical diagnoses. R E S U L T S STUDIES OF INTERVENTIONS FOCUSED ON CHIL- DREN The studies focusing on children aimed to facilitate different aspects of communication development. Each aspect targeted will be discussed separately. Pre-intentional communication Richman 1977aimed to increase a child s amount of eye contact, time she kept her head in an upright position and her imitative vocalisations. These behaviours were compared with control of drooling, which received no intervention. Wide variation was seen in each of the behaviours across baseline. Increases in each behaviour were observed during their individual intervention phases. 8

11 Behaviours reduced during reversal and then increased again once the treatment was recommenced. However, during the second treatment phase behaviours did not reach the levels of the initial treatment phase. Follow-up at one month after intervention had ceased showed similar levels to the second treatment phase for head control and imitative vocalisation. Increased scores were observed for the three behaviours at twelve month follow-up. Communicative functions Hunt 1986, Pinder 1995 and Sigafoos 1995 all trained children to produce requests. Hunt 1986 taught one girl to make requests for objects or actions in a multiple baseline design. Baseline was stable, showing infrequent use of any of the requests. The first request showed a steady increase and reached criterion (three successive correctly produced requests) in 16 sessions, the second in the sequence was produced without direct teaching. The third request in the sequence also increased steadily in the intervention phase reaching criterion in 13 sessions. The final request also generalised without direct teaching. Pinder 1995 taught four children to request either an object or more by looking at the adult and the object, the untaught request acted as a control. Requests were taught in play with toys and also assessed in snack time as a generalisation situation. Baselines were stable for three of the children, with requests made to less than 20% of probes. For one child, who had earlier been taught to make the same requests by actively reaching towards an object, increases in the target behaviour appear to have been made towards the end of baseline. For each of the four children increases in the production of both the taught and untaught requests were observed during intervention across both the treatment and generalisation situations. For two children increases were noted with the onset of intervention. For the other two increases in the behaviours were observed after 3-4 sessions of therapy. Levels of requests were maintained for four weeks after therapy had been withdrawn. Sigafoos 1995 aimed to teach a boy to use three requests for objects in a multiple baseline design. During baseline percentage correct production of the three requests (not separated) ranged from 0-35%. For the first request production increased to 35-60% with verbal prompting and increased to % when expectant delay was used and verbal prompts were faded. However, although requests increased from the first to the second phase of intervention they showed a downward trend in the latter part of the second phase. The other target requests were tested after intervention for the first and were correct for 65 and 30% of 17 trials, showing some generalisation. The trial was then stopped due to the school year ending. Davis 1998 trained a boy to produce responses to statements in conversation partners in a multiple baseline design across three communication partners, by pairing obligatory requests (questions) with a nonobligatory request (statement). Prior to intervention responses to statements were rare, being produced following 0-20% of statements made by each of the three partners in conversation (means = 1.8, 2.5 and 4.0%). During intervention responses immediately increased, following an average of 41.7% and 52% of statements by the first two partners. Increases were only observed with the individual partners once the treatment had started. However, there was considerable variation in frequency of responses during intervention, ranging from 0-60 and 20-80% with each partner. Intervention was not carried out with the third partner due to the child s family moving away from the area in which the research was conducted. Responses to statements with this partner remained at baseline level throughout the study. Hurlbut 1982 trained 3 children to use Bliss and iconic symbols to name objects. For each child trials to criterion were faster for iconic symbols than Bliss. Each child also produced iconic symbols more frequently than Blissymbols in maintenance and generalisation probes, and named more untrained objects using iconic symbols than Bliss. Expressive language Campbell 1982 taught one child to use is/are in three linguistic structures in a multiple baseline design. In baseline is/are were produced correctly in 0-10% of wh questions, 0-10% of yes/no reversal questions and 0-35% of statements. For the first two structures baselines were stable, whereas statements seemed to show an upward trend in correct production. During intervention the percentage of correct productions rose steeply for all three targeted structures. Levels were also maintained at a much higher rate than baseline for these structures, but showed considerable variation during the maintenance phase. Generalisation to use in spontaneous speech showed increases from baseline for wh and yes/no questions, but much lower levels than observed in intervention. Wide variation was noted for the generalisation of is/are in statements, with no clear pattern observed during baseline, treatment or maintenance phases. THERAPY FOCUSING ON COMMUNICATION PART- NERS Parents Basil 1992, Hanzlik 1989 and McCollum 1984 all trained parents, hoping to change their interaction style and thus facilitate children s communication. Basil 1992 found no difference between the percentage of turns taken in conversation, or the proportion of responses to children s utterances by trained parents or untrained teachers before and after intervention. Parents asked fewer open questions than teachers prior to therapy, but increased these after intervention whilst teachers use of open questions remained stable ( F (3,1) = 8.35, p = 0.063). After one hour of instruction parents in Hanzlik 1989 changed behaviour that related to doing, but not that which involved verbal interaction. Mothers who received instruction on changing physical and verbal interaction used less physical guidance (F(1,18) = 6.34, p = 0.02), more face to face contacts (F(1,18) = 28.49, p = ) and less physical contact (F(1,18) = 10.11, p = 0.005) than mothers in the control group who received neurodevelopmental therapy. No differences were observed in mothers verbal directiveness, praise, questions or verbal interaction before and after instruction for either 9

12 group. McCollum 1984 trained a mother to bring her face close to her child s. The behaviour increased from baseline and was maintained after intervention had finished. The mother s imitation of her child s vocalisation increased during intervention but showed a lot of variation, and a possible downward trend towards the end of treatment. The skills appeared to generalise to an untreated play situation, but were not maintained once treatment had stopped. Teachers and educational assistants Teachers and educational assistants who received training in Mc- Conachie 1997 used more strategies to facilitate children s communication four months after training (X 2 (4) = p = <0.01). Post-hoc analysis suggested that these differences were already observable for teachers at one month post training, but not for assistants (X 2 (4) 11.82, p <0.01). Teachers and assistants who did not receive training showed no changes in their communication patterns. Secondary outcomes for children Basil 1992, Hanzlik 1989 and McCollum 1984 also looked at changes in children s communication that were associated with training given to parents. In Basil 1992 prior to parent training children failed to respond to parents interaction more often than to teachers, but increased their responses to parents after intervention (F (3,1) = 17.94, p = 0.024). Similarly, children communicated less often using their symbol communication boards with their parents than with their teachers, but their use with parents increased after training (F (3,1) = 16.93, p = 0.026). Hanzlik 1989 observed an increase in voluntary responsiveness (F ( 1,18) = 11.53, p <0.003) and less physically directed compliance (F (1,18) = 4.44, p <0.05) but no differences in the amount of independent play for the infants whose mothers had received interaction training. The child in the study by McCollum 1984 showed an increase in vocalisation concurrent with his mother s training and increase in the frequency with which she brought her face close to her childs. D I S C U S S I O N PRINCIPAL FINDINGS This exploratory review found twelve studies that investigated the effects of different methods of SLT for children with cerebral palsy, who differed in age, type and severity of cerebral palsy, or their communication partners. Seven of these studies evaluated therapy that focused on individual children. Five studies concentrated on adult conversational partners (one study contained data subsumed into another trial and the larger study only is discussed). Therapy for children targeted pre-intentional communication skills, the use of individual communicative functions and expressive language. Training for conversational partners included parents and education workers, teaching them to facilitate the communication of individual target children, usually augmentative communication system users. Although trends in communication change were observed the methodological quality of the studies included in the review is generally poor and this review provides insufficient evidence to support the general effectiveness of SLT for either children with cerebral palsy or their communication partners. The subjects of the studies included in the review are heterogeneous and are generally poorly described. Consensus on the description of subjects and the choice of outcome measures in research reports is needed to establish potential clinical subgroups. Children and conversational partners within subgroups may resemble those with other primary disorders, for example children with severe cognitive impairment. Consensus is needed on the aims and methods of standard therapies targeting different areas of communication used with clinical subgroups. Once consensus is gained, investigations of the effectiveness of standard therapies can be developed. Consensus among committees of practice could be gained through focus groups followed by a survey of SLTs working in the clinical field. New therapy techniques should be applied in single case experimental designs, which should be rigorously designed and reported. These need to be replicated with similar subjects, from a defined clinical subgroup, and evaluated in exploratory trials. Should they show positive findings, the intervention should be tested in pragmatic trials. Subjects in trials of SLT interventions should be followed up to evaluate the long term impact of therapy. The acceptability of interventions for families has not been evaluated and needs further study. THERAPY FOCUSING ON CHILDREN Seven studies were found that investigated the effects of therapy given directly to children. All used single case experimental designs to show the impact of treatment for individual children. Children included in the studies ranged in age from infancy to late teens, had moderate to severe cerebral palsy, mild to severe speech, language and communication disorders and intellectual impairment ranging from mild to severe. Although each of the studies has methodological flaws, the provision of therapy does seem to be associated with increases in the production of pre-intentional communication behaviours (Richman 1977), requests for objects or actions (Hunt 1986, Pinder 1995), responses to others communication (Davis 1998) and use of expressive language structures (Campbell 1982) for the individual children studied. For three teenage children with severe cognitive impairment it appeared that iconic communication symbols were easier to acquire than Bliss symbols (Hurlbut 1982). As the studies used single case methodology we can only conclude that the intervention employed in the studies may have been effective in helping the individual children involved to develop communication skills. Given the methodology employed we cannot extend the findings to other children 10

13 with cerebral palsy. Replication of the studies with other subjects and exploratory group studies are needed to generalise findings to possible clinical subgroups, and move from hypothesis generation to hypothesis testing. TRAINING FOR CONVERSATION PARTNERS The studies identified that focused on communication partners involved training in facilitating the communication skills of individual children for parents, teachers and education assistants. Three studies were group trials, one study used single case experimental design. Three of the studies (Basil 1992, McCollum 1984 and McConachie 1997) have serious methodological flaws and cannot demonstrate the effects of therapy for the subjects who participated. The fourth study, by Hanzlik 1989, involved parents receiving a one hour individual training session focusing on the use physical and verbal interaction techniques. Results suggest that following the short period of intervention mothers changed their interaction style using more face to face communication and less physical contact. Overall, interaction was rated as more positive following training, but use of verbal interaction strategies did not appear to change. Follow-up was not included in the study, therefore it is not possible to determine if change was maintained for the participants or if children s communication development was facilitated. Replication of this study with follow-up is needed to investigate the effectiveness of the training programme used. Further, more rigorous investigations are also needed of the training given in the other studies, as they aimed to teach the same communication strategies, which are widely acknowledged by clinicians to affect the communication of children with speech disorders and cerebral palsy. METHODOLOGICAL QUALITY OF INVESTIGATIONS Subjects Children with cerebral palsy who receive SLT range in age from infancy to late teens and vary widely in their functional levels of movement, learning, communication, vision and hearing. When reporting new interventions it is necessary to describe for whom they may be suitable. However, the descriptions of children and adults who participated in the studies included in this review were generally poor. It would therefore not be possible to replicate most studies or to decide whether children on clinical caseloads were similar to those in the original study and may benefit from the intervention. Descriptions of subjects should include all features that may confound studies. This includes children s chronological age, type and severity of cerebral palsy, gross and fine motor functioning, cognitive developmental level, presence, type and severity of epilepsy, sensory skills, receptive and expressive language development, educational placement and previous therapy. Communication skills should be described in detail, and should include measures of speech intelligibility, methods of communication used and communicative functions produced in conversation. For training of conversation partners details of their relationship to target children, gender, educational level, previous training and present communication style should be given. With such descriptions it may be possible to identify clinical subgroups of children with cerebral palsy who display similar skills and who react to interventions in similar manners. However, as cerebral palsy is associated with a wide range of disorders it is possible that some children will not fit into such groups and the evaluation of interventions for them will comprise N of 1 trials. Intervention The interventions investigated in the studies included in this review were generally well described and their primary features could be replicated. For therapy focusing directly on children, techniques included operant and micro teaching. Training for conversation partners included short talks, brainstorming, video examples, practice and feedback. Full description with examples of interaction during intervention would facilitate replication. However, some differences would still be likely to occur due to the fluid nature of conversation and effects of different communication environments and circumstances. Two studies (Davis 1998 and Hunt 1986) reported checks of treatment integrity, which should be included in study design to show constancy of treatment across subjects and that treatment was undertaken according to the protocol. Blinding Due to the nature of participation in therapy and training it is not possible to blind subjects and clinicians to therapy, which leaves trials of SLT, including those in this review, open to attrition bias. People may agree to participate, but withdraw when allocated to the intervention they least support. Attempts were made in each of the studies to reduce detection bias by including checks of data coding by a second rater. To improve the rigour of studies, outcomes should be assessed by persons other than those giving the therapy, who are blind to the allocation of treatment and control. Sample size The group studies in the review were exploratory in nature. However, their small sample sizes increase the risk of selection bias and they are unable to give an indication of the true variation in subject group behaviours. Thus, it will be difficult for future researchers to use the data to calculate sample sizes reliably to test the effects of similar interventions. Single case experimental design It is important to show, in these hypothesis generating studies, that intervention addresses a target behaviour and that changes in behaviour are not due to maturation. This demands the establishment of an adequate baseline, with sufficient data collection points throughout the baseline, intervention and follow-up phases, and the comparison of a treated skill with an untreated behaviour that is similar in prognostic indication. Some studies failed to show that behaviours were stable before therapy, and it is therefore possible that behaviours attributed to intervention may have developed 11

14 without it. Randomisation tests may have addressed the lack of a stable baseline, but these were not used. Other studies included control behaviours that were untreated, or treated later, which were too similar to the treated behaviour and also changed, probably as a result of the intervention. One of the studies (Richman 1977) used a motor skill which would not have been expected to show the same pattern of development as the treated communication skills. None of the studies included adequate follow-up to show the maintenance of behaviour change, which is vital if we are seeking to show the acquisition of communication skills. shown unexpected results. For example in Clarke 2001 young AAC users supported a model in which children are withdrawn from classrooms to learn new communication skills, contrary to current clinical practice in which skills are taught in normal class activities. We cannot assume from their participation alone that parents and families involved in the studies of this review view the intervention they received positively as therapy was of short duration and with minimal follow-up, making attrition due to unsuitability of treatment less likely. OUTCOME MEASURES Communication A U T H O R S C O N C L U S I O N S The aim of SLT is to improve communication. As such, outcome measures should relate to aspects of communication behaviour. Depending on the particular difficulties children experience, therapy could aim to improve a child s speech production, understanding, expressive language, voice, range of communicative functions or use of an augmentative or alternative communication system. Training for parents and other communication partners involves changing their communication patterns to give children opportunities to develop and use new communication skills. The studies involved in this review targeted different aspects of communication and used different measures to collect data about the skills trained. Even studies that looked at similar skills, for example those targeting requests for objects and actions, used different measures to collect their data. This makes replication of studies harder than if generic tools were used as clinicians and researchers need to be trained to use the tools reliably. The use of the same outcome measures across studies would also help in the collection of a bank of information about the communication of children with cerebral palsy and their conversation partners, in the formation of clinical subgroups and in the assessment of the clinical significance of reported interventions. In addition to describing the change in the individual skills targeted it would be useful if authors examined the rate of change in other areas of communication, using well known outcome measures. This would provide rates of change for individuals and groups that may or may not be associated with intervention and which may be used to aid clinical practice and to inform future research. Quality of life None of the studies included in this review examined the wider impact of therapy. In addition to investigating the change in children s communication, and that of their conversation partners it is important to examine if children and their families are happy with the intervention they receive, if they think it is worthwhile and if it is associated with positive changes in other areas of their lives. Such additional information could be gained by the use of published measures of family stress and functioning and through interviews with both parents and children. To date few such studies have been undertaken. Those which have been published have Implications for practice Considering the range of aspects of communication targeted, methods used and subjects involved in the studies included in this review, and the methodological weaknesses of the studies, it is not possible to conclude at the present time that speech and language therapy focusing on children with cerebral palsy or their communication partners is more effective than no intervention at all. However, no evidence has been found of any harmful effects of SLT for children with cerebral palsy and their families, and therapy has not been shown to be ineffective. Changes in therapy provision are not warranted given current evidence. Implications for research This exploratory review highlights the lack of rigorous research on the effectiveness of SLT that aims to improve the communication skills of children with cerebral palsy. Further research is needed to define possible clinical subgroups of children with cerebral palsy and their communication partners and to investigate the most effective methods of intervention for these subgroups. To this end a bank of research evidence is needed including: Detailed description of research subjects including their age, type and severity of cerebral palsy, gross and fine motor function, cognitive level, presence and type of epilepsy, sensory skills, receptive and expressive language skills, method of communication, range of communication skills and speech intelligibility. Where possible researchers should use the same measures across reports. Communication partners should also be described thoroughly, including information on their relationship to the child, age, gender, educational history, employment, previous training in communication, attitudes towards AAC, present communicative style. Development of valid and reliable measures of speech and communication for children with motor impairments. Definition of the methods currently used to treat different areas of communication development for (subgroups of) children with cerebral palsy and their conversational partners, gained through focus groups and surveys. 12

15 Investigation of the effectiveness of generic methods, with subgroups of children and conversational partners, in pragmatic trials. Rigorous series of single case experiments to test new interventions with clients from a potential subgroup, and for clients who do not fit inclusion criteria for identified subgroups. Exploratory trials of new interventions with groups of children/ conversational partners to investigate the feasibility of using the new therapy in typical clinical situations and of extending the therapy to a group of clients who vary more than those involved in a single case series. If positive results are achieved these studies would lead to pragmatic trials comparing new and standard therapies for subgroups of children/conversation partners. Follow-up of subjects for at least three months after therapy to investigate the maintenance of skills development. Qualitative research studies to investigate children s and families perceptions of intervention techniques and evaluate their need for these interventions. Research must be rigorously conducted to allow readers to infer whether intervention is associated with communication change for children with cerebral palsy and/or their conversation partners. As this review has shown, SLT for children with cerebral palsy is a complex intervention. Children have complex communication disorders, arising from their varied underlying impairments, and each disorder may require a different type of treatment. In addition, children will experience different social relationships and interact with many different people in many different environments, each of which will influence communication and its treatment. It is probable that because of the heterogeneity of the children, their conversational partners and their communicative environments, and the interaction between these variables, that a broad evaluation of the effectiveness of SLT for children with cerebral palsy may not be possible. Instead, evaluations should concentrate on the effectiveness of interventions given to ameliorate disorders affecting different areas and stages of speech, language and communication development for groups of clients with particular sets of skills and needs. P O T E N T I A L C O N F L I C T O F I N T E R E S T None A C K N O W L E D G E M E N T S We thank the anonymous referees who provided helpful comments on the draft of the review; Helen McConachie, Nicola Jolleff, Pam Hunt, Carol Davis, Jodie Hanzlik for providing additional information about the included studies, and all the researchers who provided information about conference reports. S O U R C E S O F S U P P O R T External sources of support Royal College of Speech and Language Therapists UK Internal sources of support No sources of support supplied R E F E R E N C E S References to studies included in this review Basil 1992 {published data only} Basil C. Social interaction and learned helplessness in severely disabled children. Augmentative and Alternative Communication 1992; 8(3): Campbell 1982 {published data only} Campbell CR, Stremel-Campbell K. Programming loose training as a strategy to facilitate language generalization. Journal of Applied Behavior Analysis 1982;15(2): Davis 1998 {published and unpublished data} Davis CA, Reichle J, Southard K, Johnston S. Teaching children with severe disabilities to utilize nonobligatory conversational opportunities: an application of high-probability requests. Journal of the Association for Persons with Severe Handicaps 1998;23(1): Hanzlik 1989 {published and unpublished data} Hanzlik JR. The effect of intervention on the free-play experience for mothers and their infants with developmental delay and cerebral palsy. Physical and Occupational Therapy in Pediatrics 1989;9(2): Hunt 1986 {published and unpublished data} Hunt P, Goetz L, Alwell M, Sailor W. [Using an interrupted behavior chain strategy to teach generalized communication responses]. Journal of the Association for Persons with Severe Handicaps 1986;11 (3): Hurlbut 1982 {published data only} Hurlbut BI, Iwata BA, Green JD. Nonvocal language acquisition in adolescents with severe physical disabilities: Blissymbol versus iconic stimulus formats. Journal of Applied Behavior Analysis 1982;15(2):

16 McCollum 1984 {published data only} McCollum JA. Social interaction between parents and babies: validation of an intervention procedure. Child: Care, Health & Development 1984;10(5): McConachie 1997 {published and unpublished data} McConachie H, Pennington L. In-service training for schools on augmentative and alternative communication. European Journal of Disorders of Communication 1997;32(3): Pennington 1996a {published data only} Pennington L, McConachie H. Evaluating My Turn to Speak, an in-service training programme for schools. European Journal of Special Needs Education 1996;11(2): Pinder 1995 {published data only} Pinder GL, Olswang LB. Development of communicative intent in young children with cerebral palsy: a treatment efficacy study. Infant- Toddler Intervention 1995;5(1): Richman 1977 {published data only} Richman JS, Kozlowski NL. Operant training of head control and beginning language for a severely developmentally disabled child. Journal of Behavior Therapy & Experimental Psychiatry 1977;8(4): Sigafoos 1995 {published data only} Sigafoos J, Couzens D. Teaching functional use of an eye gaze communication board to a child with multiple disabilities. British Journal of Developmental Disabilities 1995;81(2): References to studies excluded from this review Abrahamsen 1989 Abrahamsen AA, Romski MA, Sevcik RA. Concomitants of success in acquiring an augmentative communication system: changes in attention, communication, and sociability. American Journal of Mental Retardation 1989;93(5): Alant 1996 Alant E. Augmentative and alternative communication in developing countries: challenge of the future. Augmentative & Alternative Communication 1996;12(1): Amari 1999 Amari A, Slifer KJ, Gerson AC, Schenck E, Kane A. Treating selective mutism in a paediatric rehabilitation patient by altering environmental reinforcement contingencies. Pediatric Rehabilitation 1999;3 (2): Bedrosian 1997 Bedrosian JL. Language acquisition in young AAC system users: issues and directions for future research. Augmentative & Alternative Communication 1997;13(3): Bedrosian 1999 Bedrosian JL. Efficacy research issues in AAC: interactive storybook reading. Augmentative & Alternative Communication 1999;15(1): Bishop 1994 Bishop K, Rankin J, Mirenda P. Impact of graphic symbol use on reading acquisition. Augmentative & Alternative Communication 1994;10 (2): Blackstone 1994 Blackstone SW. AACs and the ABCs... alternative and augmentive communication. Rehab Management: The Interdisciplinary Journal of Rehabilitation, 1994;7(1): Boose 1999 Boose MA, Stinnett T. Indirect Language Stimulation (ILS): AAC Techniques To Promote Communication Competence. Paper presented at the Annual Southeast Augmentative Communication Conference. Birmingham, AL: Oct 1-2, [MedLine: 80. Bruno 1989 Bruno J. Customizing a Minspeak system for a preliterate child: a case example. Augmentative & Alternative Communication 1989;5(2): Bruno 1998 Bruno J, Dribbon M. Outcomes in AAC: evaluating the effectiveness of a parent training program. Augmentative & Alternative Communication 1998;14(2): Buzolich 1991 Buzolich MJ, King JS, Baroody SM. [Acquisition of the commenting function among system users]. Augmentative & Alternative Communication 1991;7(2): Buzolich 1994 Buzolich MJ, Lunger J. [Empowering system users in peer training]. Augmentative & Alternative Communication 1994;11(1): Carter 1998 Carter M, Maxwell K. Promoting interaction with children using augmentative communication through a peer-directed intervention. International Journal of Disability, Development & Education 1998; 45(1): Chan 2002 Chan JS, Yau MK. A study on the nature of interactions between direct-care staff and persons with developmental disabilities in institutional care. British Journal of Developmental Disabilities 2002;48 (1): Cohen 2000 Cohen KJ, Light JC. Use of electronic communication to develop mentor-protege relationships between adolescent and adult AAC users: pilot study. Augmentative & Alternative Communication 2000; 16(4): DiCarlo 2000 DiCarlo CF, Banajee M. Using voice output devices to increase initiations of young children with disabilities. Journal of Early Intervention 2000;23(3): Dowden 1995 Dowden PA, Marriner NA. Augmentative and alternative communication: treatment principles and strategies. Seminars in Speech & Language 2000;16(2): Durand 1993 Durand V M. Functional communication training using assistive devices: effects on challenging behavior and affect. Augmentative & Alternative Communication 1993;9(3): Enderby 1981 Enderby P, Hamilton G. Clinical trials for communication aids? A study provoked by the clinical trials of SPLINK. International Journal of Rehabilitation Research 1981;4(2):

17 Erickson 1997 Erickson KA, Koppenhaver DA, Yoder DE, Nance J. Integrated communication and literacy instruction for a child with multiple disabilities. Focus on Autism and Other Developmental Disabilities 1997;12 (3): Galliers 1987 Galliers JR. Intelligent communication aid for Bliss users: a case study. International Journal of Rehabilitation Research 1987;10(4): Glennen 1985 Glennen SL, Calculator SN. Training functional communication board use: a pragmatic approach. Augmentative & Alternative Communication 1985;1(3): Goossens 1985 Goossens C, Kraat A. Technology as a tool for conversation and language learning for the physically disabled. Topics in Language Disorders 1985;6(1): Goossens 1989 Goossens C. Aided communication intervention before assessment: a case study of a child with cerebral palsy. Augmentative & Alternative Communication 1989;5(1): Hall 1997 Hall LJ, Macvean ML. Increases in the communicative behaviours of students with cerebral palsy as a result of feedback to, and the selection of goals by, paraprofessionals. Behaviour Change 1997;14 (3): Harris 1982 Harris D. [Communicative interaction processes involving nonvocal physically handicapped children]. Topics in Language Disorders 1982; 2(2): Harris 1996 Harris L, Doyle ES, Haaf R. Language treatment approach for users of AAC: experimental single-subject investigation. Augmentative & Alternative Communication 1996;12(4): Heim 1990 Heim M. Communicative skills of nonspeaking CP children: a study on interaction. Paper presented at 4th Biennial ISAAC International Conference on Augmentative and Alternative Commuication. Stockholm, Sweden: August 12-16, [MedLine: 303. Hetzroni 2000 Hetzroni OE, Belfiore PJ. Preschoolers with communication impairments play Shrinking Kim: an interactive computer storytelling intervention for teaching Blissymbols. Augmentative & Alternative Communication 2000;16(4): Hooper 1987 Hooper J, Connell TM, Flett PJ. Blissymbols and manual signs: a multimodal approach to intervention in a case of multiple disability. Augmentative & Alternative Communication 1987;3(2): Horn 1996 Horn EM, Jones HA. Comparison of two selection techniques used in augmentative and alternative communication. Augmentative & Alternative Communication 1996;12(1): Hsieh 1999a Hsieh M, Luo C. Morse code text typing training of a teenager with cerebral palsy using a six-switch Morse keyboard. Technology & Disability 1999;10(3): Hsieh 1999b Hsieh MC, Luo CH. Morse code typing training of an adolescent with cerebral palsy using microcomputer technology: case study. Augmentative & Alternative Communication 1999;15(4): Hulme 1989 Hulme JB, Bain B, Hardin M, McKinnon A. The influence of adaptive seating devices on vocalization. Journal of Communication Disorders 1989;22(2): Hunt 1996 Hunt P, Alwell M, Farron-Davis F, Goetz L. [Creating socially supportive environments for fully included students who experience multiple disabilities]. Journal of the Association for Persons with Severe Handicaps 1996;21(2): Hunt 2002 Hunt P, Soto G, Maier J, Muller E, Goetz L. [Collaborative teaming to support students with augmentative and alternative communication needs in general education classrooms]. Augmentative & Alternative Communication 2002;18(1): Iacono 1993 Iacono T, Mirenda P, Beukelman DR. Comparison of unimodal and multimodal AAC techniques for children with intellectual disabilities. Augmentative & Alternative Communication 1993;9(2): Jeffries 1987 Jeffries K. Assessing the effects of teaching a learning disabled child. British Journal of Special Education 1987;14(1, Research Supplement): Jouannaud 1972 Jouannaud B, Bregeon F, Tardieu C, Tardieu C. Development of imitative lingual praxias in the normal child: application to their evaluation in the disturbances of speech in cerebral palsy Evolution des praxies linguales d imitation chez l enfant normal: application a leur evaluation dans les troubles du langage de l infirme moteur cerebral. Revue de Neuropsychiatrie Infantile et d Hygiene Mentale de l Enfance 1972;20(8-9): Kaiser 1993 Kaiser A, Ostrosky MM, Alpert CA. [Training teachers to use environmental arrangement and mileu teaching with nonvocal preschool children]. Journal of the Association for Persons with Severe Handicapa 1993;18(3): Ketelaar 1998 Ketelaar M, Vermeer A, Helders PJ, Hart H. Parental participation in intervention programs for children with cerebral palsy: a review of research. Topics in Early Childhood Special Education 1998;18(2): King 1997 King GA, Specht JA, Schultz I, Warr-Leeper G, Redekop W, Risebrough N. Social skills training for withdrawn unpopular children with physical disabilities: a preliminary evaluation. Rehabilitation Psychology 1997;42(1): King 1998 King G, Tucker MA, Alambets P, Gritzan J, McDougall J, Ogilvie A, Husted K, O Grady S, Brine M, Malloy-Miller T. The evaluation of functional, school-based therapy services for children with special needs: a feasibility study. Physical & Occupational Therapy in Pediatrics 1998;18(2):

18 16

19 Kozleski 1991 Kozleski EB. [Expectant time delay for teaching requests]. Augmentative & Alternative Communication 1991;7: Kratzer 1993 Kratzer DA, Spooner F, Test DW, Koorland MA. [Extending the application of constant time delay: teaching a requesting skill to students with severe multiple disabilities]. Education and Treatment of Children 1993;16(3): Lagerman 1982 Lagerman U, Hook O. Communication aids for patients with dys/anarthria. Scandinavian Journal of Rehabilitation Medicine 1982; 14(4): Lancioni 2001 Lancioni GE, O Reilly MF, Oliva D, Coppa MM. A microswitch for vocalization responses to foster environmental control in children with multiple disabilities. Journal of Intellectual Disability Research 2001;445(3): Light 1999 Light JC, Binger C, Agate TL, Ramsay KN. Teaching partner-focused questions to individuals who use augmentative and alternative communication to enhance their communicative competence. Journal of Speech, Language, & Hearing Research 1999;42(1): Lovett 1994 Lovett MW, Barron RW, Forbes JE, Cuksts B, Steinbach KA. Computer speech-based training of literacy skills in neurologically impaired children: a controlled evaluation. Brain and Language 1994; 47(1): McCarthy 2001 McCarthy J, Light J. Instructional effectiveness of an integrated theater arts program for children using augmentative and alternative communication and their nondisabled peers: preliminary study. Augmentative & Alternative Communication 2001;17(2): McEwen 1989 McEwen IR, Karlan GR. Assessment of effects of position on communication board access by individuals with cerebral palsy. Augmentative and Alternative Communication 1989;5(4): McNairn 2000a McNairn P, Shioleno C. Augmentative communication - part one. Part 1: can we talk? Parents perspectives on augmentative and alternative communication. Exceptional Parent 2000;30(2): McNairn 2000b McNairn P, Shioleno C. Augmentative communication -- part two. Can we talk? Parents perspectives on AAC: making sense of technology and making it work. Exceptional Parent 2000;30(3): McNairn 2000c McNairn P, Shioleno C. Augmentative communication - part three. Can we talk? Parents perspectives on AAC: selecting the right system, now and as your child grows. Exceptional Parent 2000;30(4): Mitchell 1995 Mitchell PR, Mahoney G. Team management for young children with motor speech disorders. Seminars in Speech and Language 1995; 16(2): Okimoto 2000 Okimoto AM, Bundy A, Hanzlik J. Playfulness in children with and without disability: measurement and intervention. American Journal of Occupational Therapy 2000;54(1): Olswang 1995 Olswang LB, Pinder GL. Preverbal functional communication and the role of object play in children with cerebral palsy. Infant-Toddler Intervention 1995;5(3): Oxley 2000 Oxley JD, Norris JA. Children s use of memory strategies: relevance to voice output communication aid use. Augmentative & Alternative Communication 2000;16(2): Pahn 1972 Pahn E, Pahn J. Die phoniatrische Spatbehandlung zerebralparetischer, spastischer Kinder. Folia Phoniatrica 1972;24(1): Palmer 1997 Palmer FB. Evaluation of developmental therapies in cerebral palsy. Mental Retardation and Developmental Disabilities Research Reviews 1997;3(2): Park 1979 Park GC, Roy OZ, Warrick A, Cote C. Mechanical pointer for use with handicapped children. Medical & Biological Engineering & Computing 1979;17(2): Paul 1997 Paul R. Facilitating transitions in language development for children using AAC. Augmentative & Alternative Communication 1997;13(3): Ratcliff 1996 Ratcliff A, Little M. A conversation based barrier task approach to teach sight-word vocabulary to a young augmentative communication system user. Child Language Teaching & Therapy 1996;12(2): Reichle 1999 Reichle J, Johnston SS. Teaching the conditional use of communicative requests to two school-age children with severe developmental disabilities. Language, Speech & Hearing Services in the Schools 1999; 30(4): Reinhartsen 1997 Reinhartsen DB, Edmondson R, Crais ER. Developing assistive technology strategies for infants and toddlers with communication difficulties. Seminars in Speech & Language 1997;18(3): Romski 1988 Romski MA, Sevcik RA, Pate JL. Establishment of symbolic communication in persons with severe retardation. Journal of Speech and Hearing Disorders 1988;53(1): Romski 1994a Romski MA, Sevcik RA, Robinson B, Bakeman R. Adult-directed communications of youth with mental retardation using the system for augmenting language. Journal of Speech and Hearing Research 1994;37: Romski 1994b Romski MA, Sevcik RA, Wilkinson KM. Peer-directed communicative interactions of augmented language learners with mental retardation. American Journal on Mental Retardation 1994;98(4):

20 Romski 1995 Romski MA, Sevcik RA, Robinson BF, Mervis CB, Bertrand J. Mapping the meanings of novel visual symbols by youth with moderate or severe mental retardation. American Journal on Mental Retardation 1995;100(4): Romski 1997 Romski MA, Sevcik RA. Augmentative and alternative communication for children with developmental disabilities. Mental Retardation & Developmental Disabilities Research Reviews 1997;3(4): Rowland 2000 Rowland C, Schweigert P. Tangible symbols, tangible outcomes. Augmentative & Alternative Communication 2000;16(2): Sevcik 1995 Sevcik RA, Romski MA, Watkins RV, Deffebach KP. Adult partneraugmented communication input to youth with mental retardation using the System for Augmenting Language (SAL). Journal of Speech & Hearing Research 1995;38(4): Sigafoos 1999 Sigafoos J, Roberts-Pennell D. Wrong-item format: a promising intervention for teaching socially appropriate forms of rejecting to children with developmental disabilities?. Augmentative & Alternative Communication 1999;15(2): Signorino 1997 Signorino M, Cacchio G, Ceccarani P, Asoli A, Scalini L. Neurological rehabilitation in deaf-blind patients with cerebral palsy. Developmental Brain Dysfunction 1997;10(4): Soro 1993 Soro E, Basil C. Strategies for facilitating interaction among aided speakers. [Spanish]. Infancia y Aprendizaje 1993;64: Spiegel 1993 Spiegel BB, Benjamin BJ, Spiegel SA. One method to increase spontaneous use of an assistive communication device: case study. Augmentative and Alternative Communication 1993;9(2): Sternberg 1983 Sternberg L, Pegnatore L, Hill C. [Establishing interactive communication behaviors with profoundly mentally handicapped students]. Journal of the Association for Persons with Severe Handicap 1983;8(1): Treviranus 1987 Treviranus J, Tannock R. A scanning computer access system for children with severe physical disabilities. American Journal of Occupational Therapy 1987;41(11): Udwin 1987a Udwin O. Analysis of the experimental adequacy of alternative and augmentative communication training studies. Child Language, Teaching and Therapy 1987;2(1): Udwin 1987b Udwin O, Yule W. Augmentative communication modes taught to cerebral palsied children: findings from a longitudinal study. International Journal of Rehabilitation Research 1987;10(2): Udwin 1990 Udwin O, Yule W. [Augmentative communication systems taught to cerebral palsied children - a longitudinal study: I. The acquisition of signs and symbols, and syntactic aspects of their use over time]. British Journal of Disorders of Communication 1990;25(4): Udwin 1991 Udwin O, Yule W. [Augmentative communication systems taught to cerebral palsied children - a longitudinal study: II. Pragmatic features of sign and symbol use]. British Journal of Disorders of Communication 1991;26(2): Watkins 1988 Watkins S, And Others. Educating the non-verbal child: a transdisciplinary approach. Paper presented at Annual Convention of the Council for Exceptional Children. Washington, DC: March 28-April 1, [MedLine: 772. Woods 1997 Woods DW, Fuqua RW, Waltz TJ. Evaluation and elimination of an avoidance response in a child who stutters: a case study. Journal of Fluency Disorders 1997;22(4): Worth 2001 Worth N. Fountaindale Communication Project. International Journal of Language & Communication Disorders 2001;36(Supplement 2001): Additional references Aicardi 1992 Aicardi J, Bax M. Cerebral palsy. In: Aicardi J, editor(s). Diseases of the nervous system. London: MacKeith Press, 1992: Bottos 1999 Bottos M, Granato T, Allibro G, Gioachin C, Puato ML. Prevalence of cerebral palsy in north-east Italy from 1965 to Developmental Medicine and Child Neurology 1999;41((1)): Calculator 1991 Calculator SN, Jorgensen CM. Integrating AAC instruction into regular education settings: Expounding on best practices. Augmentative and Alternative Communication 1991;7(3): Clarke 2001 Clarke M, McConachie H, Price K, Wood P. [Views of young people using augmentative and alternative communication systems]. International Journal of Language and Communication Disorders 2001;36 (1): Colver 2000 Colver AF, Gibson M, Hey EN, Jarvis SN, Mackie PC, Richmond S for the North of England Collaborative Cerebral Palsy Survey. Increasing rates of cerebral palsy across the severity spectrum in northeast England Archives of Disease in Childhood Fetal and Neonatal Edition 2000;83(1):F7 F12. Culp 1988 Culp DM, Carlisle M. PACT Partners in augmentative communication training. A resource guide for interaction facilitation training for children. Tuscon: Communication Skill Builders, Dunst 1988 Dunst C, Trivette CM. In: Marfo K, editor(s). Parent-child interaction and devlopmental disabilities. New York: Praeger, 1988:3 31. Edgington 1995 Edgington, ES. Randomization Tests. (3rd Edition). New York: Marcel Dekker,