Correlation between ICIDH handicap code and Gross Motor Function Classification System in children with cerebral palsy

Transcription

1 Correlation between ICIDH handicap code and Gross Motor Function Classification System in children with cerebral palsy Eva Beckung* PT PhD; Gudrun Hagberg BA BM PhD, Department of Pediatrics, Göteborg University, Queen Silvia s University Hospital, SU/ Östra, S- Göteborg, Sweden. *Correspondence to first author at address above. The aim of this study was to apply the International Classification of Impairments, Disabilities and Handicap (ICIDH; WHO 9) parallel to the Gross Motor Function Classification System (GMFCS; Palisano et al. 99) in a population-based series of children with cerebral palsy (CP). Of the children studied, birth characteristics, data on gross motor function, and level of handicap at to years of age, were retrospectively collected from medical records and documentation made by rehabilitation team members. Low handicap scores and mild levels of gross motor disability were present in children with hemiplegic CP, moderate scores in children with diplegic CP, simple ataxia, and athetotic CP, and high scores in children with dystonic CP and tetraplegic CP. A significant correlation was found between high handicap scores as well as high levels on the GMFCS and the presence of learning disability, epilepsy, and obvious aetiology of CP. A strong correlation was found between the handicap code and the GMFCS, the strongest concerning the dimension of mobility (r=.9, p<.). A striking similarity in the grading of disability was present between the ICIDH handicap code and the GMFCS. The GMFCS is considerably less timeconsuming and can be evaluated retrospectively. The handicap code requires more detailed information and is more useful for a comprehensive profile of the child. Finding a widely accepted method for evaluating motor function in children with cerebral palsy (CP) has always been an issue for concern. In epidemiological data of CP, the severity of gross motor impairments and disabilities are usually classified by different CP subtypes or defined as mild, moderate, or severe. The addition of two other classification systems, the International Classification of Impairments, Disabilities and Handicap (ICIDH; WHO 9) and the Gross Motor Function Classification System (GMFCS) in children with CP (Palisano et al. 99), may provide information for better planning of service provision and management. The ICIDH is relevant to the long-term consequences of disease, injuries, or disorders and is applicable both to personal health care and to the planning of long-term rehabilitation. It has been applied in a number of population surveys (Pfeiffer 9, Ferngren and Lagergren 9, Veen et al. 99, Thornburn et al. 99, Beckung and Uvebrant 99). The GMFCS has recently been developed for clinical practice in children with CP between the ages of and years, but the application of the model has, to our knowledge, not yet been documented. The aim of the study was to apply the ICIDH handicap code parallel to the GMFCS in a populationbased series of children with CP, to correlate them to main clinical parameters such as type of CP and patterns of associated neuroimpairments, and to analyse the relation between the two classification systems. CP was defined as a group of non-progressive, but often changing, motor impairment syndromes secondary to lesions or anomalies of the brain arising in the early stages of development (Mutch et al. 99, p ). The prenatal period was defined as the period from conception to the onset of the labour resulting in delivery, the peri/neonatal period as the period from the onset of labour until the th day of life, and the postnatal period as the period from the 9th day of life up to years of age. The aetiology was considered prenatal in the case of malformations of the CNS and intrauterine infections of the TORCH type (toxoplasmosis, rubella, cytomegalovirus, herpes), perinatal in the case of posthaemorrhagic hydrocephalus, intraventricular bleeding, and severe perinatal compromise and postnatal in the case of obvious damage in a child who had earlier been developing normally (see Hagberg et al. 99). Method The study area comprised the western health care region of Sweden and the county of Jönköping. The study covered the birth year period 99 to 99, in which 9 9 live births were recorded. Children with CP were included if they were born in Sweden and lived in the study area on December 99. All children were at least years of age at diagnosis. The Swedish classification of CP syndromes was applied (Mutch et al. 99). Informed consent to the study was obtained from of the children (9%; boys, girls) identified as having CP. Main birth characteristics and clinical features were collected from medical records as shown in Table I. More detailed data on gross motor function and level of disability at to years of age were collected from documentation made by habilitation team members (physiotherapists, occupational therapists, psychologists, and social workers). The ICIDH handicap code is based on a 9-point grading of six dimensions: orientation, physical independence, mobility, Developmental Medicine & Child Neurology, : 9 9

2 occupation, social integration, and economic self-sufficiency. The code was adjusted for Scandinavian children aged to years in 99 (Diedrichsen et al. 99). It has been shown to have a most satisfactory interobserver agreement (Ferngren and Lagergren 9). In this study, the dimension of economic self-sufficiency was excluded due to the financial support system in Sweden, which makes the grading difficult and the differences between families very small. The grading of mobility is shown in Table II. A total handicap score for each child was calculated as the mean of Table I: Gestational age, birthweight, aetiology, type of CP, and associated neuroimpairments in children with CP Characteristic n (%) Gestational age (wk) < 9 9 > 9 Birthweight (g) < 99 Aetiology Prenatal 9 Peri/neonatal Postnatal Unclear Type of CP Spastic Hemiplegia Diplegia Tetraplegia Dyskinetic Dystonic Athetotic Simple ataxia Associated impairments Learning disability* Severe (IQ ) Mild (IQ ) Epilepsy 9 Table II: ICIDH handicap code. Rating scale for the dimension of mobility Fully mobile Periodic restriction of mobility, i.e. slippery roads etc. Slightly reduced mobility, i.e. reduced capacity to run compared to peers Moderately reduced mobility, i.e. inability to manage stairs Neighbourhood restriction, e.g. difficult access to playground Dwelling restriction, confined to home Room restriction, confined to room Chair restriction, confined to chair Total restriction of mobility, confined to bed Other 9 A description of the complete scale categories is available in Diedrichsen et al. 99. the five dimension scores. The GMFCS in children with CP is based on a -level grading, an interrater reliability of. has been reported, and content validity has been established (Palisano et al. 99). Distinction between the different levels is focused on functional limitations and need for assistive technology including mobility devices and wheeled mobility rather than quality of movement. The main features of the five levels at to years of age are given in Table III. The non-parametric test Spearman rank correlation coefficient was used to test the relation between various parameters and the GMFCS, and between these variables and the handicap code. The parametric correlation coefficient was used to test the relation between the GMFCS and the handicap code. Results THE ICIDH HANDICAP CODE Most of the children with CP had a total handicap score below. The mean total handicap score was.; the mean handicap score in the dimension of orientation was.9, physical independence., mobility.9, occupation., and social integration.. Figures a to d show the scores according to type of CP, IQ, presence of epilepsy, and aetiology respectively. With regard to type of CP, the lowest mean scores were found in children with hemiplegic CP; moderate scores in children with diplegic CP, simple ataxia and athetotic CP; and the highest scores in children with dystonic and tetraplegic CP. Within the different types of CP there was a tendency for mobility to have the highest score and social integration the lowest one (see Fig. a). A higher handicap score correlated significantly with the presence of learning disability* (r=., p<.), Table III: GMFS for children with CP Level I Walks without restrictions; limitations in more advanced gross motor skills. Level II Walks without assistive devices; limitations walking outdoors and in the community. Level III Walks with assistive mobility devices; limitations walking outdoors and in the community. Level IV Self-mobility with limitations; children are transported or use power mobility outdoors and in the community. Level V Self-mobility is severely limited even with the use of assistive technology. Table IV: Spearman rank correlation coefficient of selected variables and the GMFCS r p value GMFCS Learning disability. <. Epilepsy. <. Obvious aetiology. <. Birthweight.. Gestational age.. *UK usage. US usage; mental retardation. Developmental Medicine & Child Neurology, : 9

3 epilepsy (r=., p<.) and obvious aetiology of CP (r=., p<.; see Figs b to d). No significant relation was found between handicap score and gestational age or birthweight. GMFCS Most of the children with CP were classified according to the GMFCS at level I and level II (% and % respectively), % at level III, % at level IV, and % at level V. The distribution of levels according to the different CP types is shown in Figure. A mild gross motor disability, defined as level I or II in the GMFCS, occurred in all children with simple ataxia, in of of those with hemiplegic CP, in about % of those with diplegic and athetotic CP, and in none of the children with tetraplegic and dystonic CP. Higher levels of the GMFCS correlated significantly with the presence of learning disability, epilepsy, and obvious aetiology of CP (Table IV). No significant relation was found between the level of the GMFCS and gestational age or birthweight. CORRELATION BETWEEN THE ICIDH HANDICAP CODE AND THE GMFCS The GMFCS correlated strongly with the total handicap score and with the scores in all the dimensions of handicap. The highest rank correlation was found for mobility (r=.9, p<.). When adjusted for the other variables, the partial correlation suggested that the association between the GMFCS and the handicap code could largely be explained by variation in mobility (Table V). Discussion Classification systems of neurodevelopmental impairments are needed to increase our understanding of causation, to evaluate the effects of interventions, and to determine the impact on society. In paediatric physiotherapy, assessment, and classification of motor function in children with CP is of great importance. Most classification systems of motor function for CP emphasize patterns of impairment (i.e. spasticity, dyskinesia, ataxia, and their location). The ICDIH model describes handicap in six dimensions in which competence is assumed to be necessary for survival. The GMFCS is based on the concepts of handicap and functional limitations, described in the Nagy model (9), the ICDIH (WHO 9), and the National Institute of Health (99). It is intended to be quick and easy to use on reported a b Or Phys Mob Occ Soc Total Or Phys Mob Occ Soc Total c d Or Phys Mob Occ Soc Total Or Phys Mob Occ Soc Total Figure : Distribution of mean handicap score in children with CP according to (a) type of CP, (b) IQ, (c) presence of epilepsy, and (d) aetiology. Or, orientation; Phys, physical independence; Mob, mobility; Occ, Occupation; Soc, social integration; Total, total handicap score. Figure a: hemiplegia, n=; diplegia, n=; tetraplegia, n=; simple ataxia, n=; dystonic CP, n=; athetotic CP, n=. Figure b: no MR, n=; MMR, n=; SMR, n=. Figure c: epilepsy, n=; no epilepsy, n=. Figure d: prenatal, n=9; perinatal, n=; postnatal, n=; unclear, n=. ICIDH and GMFCS in children with CP Eva Beckung and Gudrun Hagberg

4 or observed gross motor function rather than for standardized testing. It has been recommended for clinical practice and research as well as means of anticipating later motor function and children's needs and in making management decisions. The results from this study support the validity of the GMFCS. This study underlines the close relation between handicap and disability in children with CP. The similarity in the grading of disablement between the ICIDH handicap code and the GFMCS was striking relative to the different CP types, the presence of associated neuroimpairments, and the impact of gestational age and birthweight. From studies on CP, it is well known that of the CP syndromes, spastic hemiplegia and athetosis are the least disabling whereas dystonic CP and tetraplegia the most disabling, with regard to gross motor function (Uvebrant 9, Hagberg et al. 99). This is also demonstrated in this study. Both the handicap score and the level of GMFCS increased with the occurrence of associated impairments. As an example, the children with a mild learning disability had a mean mobility score of. and the children with a severe learning disability had a of., compared to a Table V: Partial correlation matrix for GMFCS and the five dimensions of the handicap code GMFCS Or Phys Mob Occ Orientation. Physical independence.. Mobility.9.. Occupation.... Social integration Or, orientation; Phys, physical independence; Mob, mobility; Occ, occupation. of.9 in children normally or near-normally gifted. The same association has recently been shown in a study of epilepsy in children (Beckung and Uvebrant 99). Children with a low gestational age and low birthweight had overall slightly but not significantly higher disability scores than the more mature and heavier children, well in accordance with results from Swedish studies on CP (Hagberg et al. 99). A shift in the clinical CP panorama towards more severe CP forms in preterm children coincided with the increasing survival of preterm babies beginning in the 9s. Hand function is not included in the handicap code although the ability to use the hands in a functional manner may be of more predictive value to determine the level of disability in CP. Pfeiffer (9) argues that the code is oriented too much towards gross motor functions. The total handicap score in our study seemed largely to be explained by variation in the dimension of mobility, where hand function is not reflected. The dimension of occupation applies to school but does not reflect hand function either. The GMFCS has some implications for hand function as good results in the items sitting position and need of support are prerequisites for optimal hand use. A future classification system of motor function for CP would preferably also include the level of manipulative skills. There are two main types of health status measures: objective and subjective. The ICIDH is an example of an objective health status measure. Subjective health measures are often called quality of life (QoL) measures and include the patient's own report. The ICIDH handicap code does not take the patient's own opinion into account. However, a high level of concordance between QoL scores and recording of disability as perceived by the clinician was found in the development of a lifestyle assessment questionnaire (Mackie et al. 99). Personal factors are included in the revised ICIDH model (ICDIH ), which may include more QoL components and personal and environmental factors. This model is, however, still provisional and under evaluation by professionals 9 level I level II level III level IV level V Percentage Hemiplegia Diplegia Tetraplegia Dystonic Athetotic Simple (n=) (n=) (n=) CP (n=) CP (n=) ataxia (n=) Figure : Distribution of GMFCS in children with CP according to type of CP. Developmental Medicine & Child Neurology, : 9

5 and a special adjustment for children needs to be developed. In conclusion, the classification of handicap and that of gross motor function used in this study correlated very significantly. The best correlation found was between the dimension of mobility in the handicap code and the GMFCS. The GMFCS is considerably less time-consuming than the handicap code and can easily be evaluated retrospectively. It seems to be sufficient in enabling anticipation of development and in planning interventions in children with CP which is of great help especially for inexperienced paediatric physiotherapists. The handicap code requires more detailed information from habilitation team members and is more useful for a more comprehensive profile of the child, much needed in multidisciplinary team work. Accepted for publication th February. Acknowledgements This study was supported by grants from the Axel and Margareth Ax:son Johnson Foundation and the RBU Research Foundation. We also wish to express our thanks to all colleagues at the habilitation clinics in the study region. References Beckung E, Uvebrant P. (99) Impairments, disabilities and handicap in children and adolescents with epilepsy. Acta Paediatrica :. Diedrichsen J, Ferngren H, Hansen FJ, Lindman C, Kallio T, Lagergren J, Lou H, Sjögren O. (99) The handicap code of the ICIDH, adapted for children aged years. International Disability Studies :. Ferngren H, Lagergren J. (9) Classification of handicap in year-old mentally retarded children. International Disability Studies :. Hagberg B, Hagberg G, Olow I, v Wendt L. (99) The changing panorama of cerebral palsy in Sweden: VII. Prevalence and origin in the birth year period 9 9. Acta Paediatrica : 9. Mackie PC, Jessen EC, Jarvis SN. (99) The lifestyle assessment questionnaire: an instrument to measure the impact of disability on the lives of children with cerebral palsy and their families. Child Care, Health and Development :. Mutch L. (99) Cerebral palsy epidemiology: where are we now and where are we going? Developmental Medicine & Child Neurology :. Nagi S. (9) Some conceptual issues in disability and rehabilitation. In: Sussman M. editor. Sociology and Rehabilitation. Washington, DC: American Sociological Association. p. National Institutes of Health. (99) Reseach Plan for the Centre for Medical Rehabilitation Research. NIH Publication no 9-9. Bethseda, MD: National Institute of Health. Palisano R, Rosenbaum P, Walter S, Russell D, Wood E, Galuppi B. (99) Development and reliability of a system to classify gross motor function in children with cerebral palsy. Developmental Medicine & Child Neurology 9:. Pfeiffer J. (9) Functional evaluation of cerebral palsy using the ICIDH. International Rehabilitation Medicine :. Thornburn MJ, Desai P, Davidson L. (99) Categories, classes and criteria in childhood disability-experience from a survey in Jamaica. Disability and Rehabilitation :. Uvebrant P. (9) Hemiplegic cerebral palsy. Etiology and outcome. Acta Paediatrica Scandinavica. (Suppl.): Veen S, Ens-Dokkum M, Schreuder A, Verloove-Vanhoric S, Brand R, Ruys J. (99) Impairments, disabilities and handicap of very preterm and very-low-birthweight infants at five years of age. Lancet :. World Health Organization. (9) International Classification of Impairments, Disabilities and Handicaps. Geneva: World Health Organization. ICIDH and GMFCS in children with CP Eva Beckung and Gudrun Hagberg