),1$/5(3257'HFHPEHU±0DUFK. Joan G.M. Deckers François G. Schellevis

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Project title: Project number: Contract number: Programme: Institute: Project coordinator: Project leader: Health information from primary care 2001/IND/2096 SI2.326354 (2001CVG3-508) Health Monitoring Directorate General SanCo European Commission Netherlands Institute for Health Services Research (NIVEL) PO Box 1568 3500 BN UTRECHT the Netherlands Tel + 31 30 2729 700 Fax + 31 30 2729 729 Joan G.M. Deckers François G. Schellevis ISBN 90-6905-679-8 http://www.nivel.nl nivel@nivel.nl 2004 NIVEL, Postbus 1568, 3500 BN UTRECHT 7KLVUHSRUWZDVSURGXFHGE\DFRQWUDFWRUIRU+HDOWK &RQVXPHU3URWHFWLRQ'LUHFWRUDWH *HQHUDODQGUHSUHVHQWVWKHYLHZVRIWKHDXWKRU7KHVHYLHZVKDYHQRWEHHQDGRSWHGRULQ DQ\ZD\DSSURYHGE\WKH&RPPLVVLRQDQGGRQRWQHFHVVDULO\UHSUHVHQWWKHYLHZRIWKH &RPPLVVLRQRUWKH'LUHFWRUDWH*HQHUDOIRU+HDOWKDQG&RQVXPHU3URWHFWLRQ7KH (XURSHDQ&RPPLVVLRQGRHVQRWJXDUDQWHHWKHDFFXUDF\RIWKHGDWDLQFOXGHGLQWKLVVWXG\ QRUGRHVLWDFFHSWUHVSRQVLELOLW\IRUDQ\XVHPDGHWKHUHRI

Contents ([HFXWLYH6XPPDU\ $EEUHYLDWLRQV,QWURGXFWLRQ 1.1 Background 9 1.2 Project aims 10 1.3 Participants and meetings 10 1.4 Overview of the report 11 'HVFULSWLRQRISULPDU\FDUHUHJLVWUDWLRQQHWZRUNV 2.1 Summary 13 2.2 Background 13 2.3 Purpose 14 2.4 Methods 15 2.5 Findings 15 2.6 Future of primary care networks 19 2.7 Conclusion 19 3ULPDU\FDUH±VLWXDWLRQLQVHYHQ(XURSHDQFRXQWULHV 3.1 Summary 21 3.2 Background 21 3.3 Purpose 22 3.4 Methods 22 3.5 Findings 23 3.6 New developments 25 3.7 Conclusion 26 'HYHORSPHQWRIKHDOWKLQGLFDWRUSURILOHV 4.1 Summary 27 4.2 Background 27 4.3 Purpose 28 4.4 Methods 28 4.5 Results 28 4.6 Conclusion 31,QWHUQDWLRQDOFRPSDULVRQRIGLVHDVHV 5.1 Summary 33 5.2 Introduction 33 5.3 Methods and general results 34 5.4 Asthma 35 5.5 Low back pain 36 5.6 Chickenpox 38!"$#%&('*) +,+- 3

5.7 Depression 40 5.8 Diabetes mellitus 41 5.9 Gastroenteritis 44 5.10 Herper zoster 46 5.11 Stroke 47 5.12 Conclusion 49 &RQFOXVLRQVDQGUHFRPPHQGDWLRQV 6.1 Introduction 51 6.2 Primary care networks 51 6.3 Primary care in seven European countries 52 6.4 Health indicator profiles 52 6.5 International comparison of diseases 53 6.6 Future developments 53 6.7 Final conclusion 54 $FNQRZOHGJPHQWV 5HIHUHQFHV $SSHQGLFHV 4!"$#%&('*) +,+-

([HFXWLYH6XPPDU\ This is the final report of the project Health Information from Primary Care which was carried out between December 1, 2001 and March 31, 2004 as part of the Health Monitoring sub-programme of the Public Health Programme 1998-2002 of the European Commission (Directorate-General Health and Consumer Protection). 2EMHFWLYH The objective of the project was (1) to establish the appropriateness of information from routine primary care as a source for epidemiological data on European Community Health Indicators and (2) to develop and test the feasibility of Health Indicator Profiles for establishing the validity and comparability of the information from Member States. A secondary aim was to extend the project activities to EU Member States which cannot deliver these epidemiological data so far. $FWLYLWLHV The project activities included the following: (1) collect epidemiological information for eight selected diseases in eight primary care based networks; (2) perform site visits with standardised questionnaires and checklist to the participating primary care networks to collect methodological and circumstantial information about the provided epidemiological data; (3) develop Health Indicator Profiles for the selected diseases to clarify the appropriateness of primary care as source of epidemiological information and (4) to provide information on the validity and international comparability of information from primary care; (5) contact representatives from non-participating countries in order to study the possibilities of collecting and/or delivering data from primary care, (6) formulate recommendations on data collection and data analysis by primary care networks and the suitability of primary care as information source. 5HVXOWV The results of the project can be summarised as follows: œ Eight primary care networks in Belgium, England & Wales, France (two networks), Germany, the Netherlands, Portugal and Spain delivered epidemiological information. In general, the networks comprise a stable group of general practitioners and monitor a representative sample of the general population (either at regional or national level). All networks apply procedures to ensure the quality of the collected data; œ Epidemiological information was obtained for acute diarrhoea/gastroenteritis, asthma, low back pain, chickenpox, depression, diabetes mellitus, herpes zoster and stroke/tia. For these conditions information was available from at least three countries in the period 1995-2002; œ Specific health indicator profiles (HIPs) have been developed for each disease. These profiles contain information on epidemiological, clinical and contextual information per country;!"$#%&('*) +,+- 5

!"$#%&('*) +,+œ œ Health indicator profiles were applied to the information obtained for the selected diseases. The least variation in clinical and contextual information was observed for chickenpox, diabetes mellitus, herpes zoster and stroke. The incidence rates for these diseases were to a large extent comparable or differences could be explained. The clinical and contextual information for asthma, low back pain, depression and gastroenteritis showed more variation in the incidence rates. When comparing primary care based morbidity data from different countries, differences with regard to the primary care context have to be taken into account. Although in most countries primary care is the entry point to the health care system, the number of directly accessible health care professionals providing diagnostic services, including the general practitioner, is variable between countries; A follow-up project concerning the provision of data from electronic medical records in primary care not only has participants from Spain, England & Wales, France and the Netherlands but also from Denmark, Italy and Malta. &RQFOXVLRQVDQGUHFRPPHQGDWLRQV œ Primary care networks can fill the information gap between population-based health information and hospital-based data; œ Minimum criteria that need to be fulfilled in order to establish a reliable primary care network include continuous surveillance of public health issues. Age and gender specificity is required for most conditions and the epidemiological denominator needs to established in a reliable way. The frequency of reporting depends on the disease but has to be at least annually and should be more frequent in case of infectious diseases. Lastly quality measures need to be in place; œ Structural funding is an essential prerequisite to establish and maintain a network; œ In those countries where the general practitioner does not function as a gatekeeper we recommend the inclusion of directly accessible specialists like paediatricians and gynaecologists in a primary care network; œ Health indicator profiles have been developed as a generic model to facilitate and validate international comparisons. Although developed for primary care, its use can be extended beyond that; œ Primary care networks can be used as an information source for chickenpox, diabetes mellitus, herpes zoster and stroke. More validation and harmonisation of findings for low back pain, chickenpox, depression and gastroenteritis has to be performed before primary care can be used as a valuable information source for these conditions. We expect the influences of different health care systems and cultural background to be smallest for somatic diseases affecting adults; œ Primary care networks can have a role in public health monitoring and therefore strongly advise the implementation of a primary care network in each country. 6

$EEUHYLDWLRQV $EEUHYLDWLRQ 'HVFULSWLRQ A&E Accidents and emergency BE Belgium COPD Chronic obstructive pulmonary disease CVA Cerebrovascular accident DE Germany DM Diabetes mellitus E&W England & Wales EC European commission ECHI European community health indicators EISS European influenza surveillance scheme ES Spain ES-CyL Spain (region Castilla & Léon) ES-MA Spain (region Madrid) ES-PV Spain (region Basque Country) ES-VA Spain (region Valencia) EUPHIN/HIEMS European union public health information network / health indicators exchange and monitoring system FR-I France Inserm FR-OR France Open Rome fte Full-time equivalent GP General practitioner HES Health examination survey HIP Health indicator profile HIS Health interview survey ICD International classification of disease ICPC International classification of primary care IOM Institute of medicine LBP Low back pain NIVEL Netherlands institute for health services research NL the Netherlands NL-NS2 the Netherlands (2 nd Dutch National Survey of General Practice) OMG Observatoire de la médecine générale PT Portugal SESAM Sächsischen epidemiologischen Studie in der Allegemeinmedizin SFMG la Société Française de médecine générale STD Sexually transmitted disease TIA Transient ischemic attack WHO World health organization WONCA World organization of family doctors!"$#%&('*) +,+- 7

8!"$#%&('*) +,+-

,QWURGXFWLRQ %DFNJURXQG The Health Information from Primary Care project was funded by the European Commission, DG Sanco as part of the Community Action Programme on Health Monitoring (adopted 1997-2002). The objective of the programme ZDVµ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previous project ( Health Monitoring in Sentinel Practice Networks ) performed by our institute has made an inventory of primary care networks that collect primary care based data related to health status (i.e. morbidity) on a continuous basis. 2 Furthermore in this project a pilot study has been performed on the international comparability of disease data collected by primary care networks. In the scope of another project within the framework of the Health Monitoring Programme a set of European Community Health Indicators (ECHI) has been developed to prepare a Community health data exchange system. 3 This proposed list of health indicators includes diseases responsible for a large share of the burden of ill health and diseases related to certain risk factors or issues of prevention and health care. The need for comparable epidemiological data is identified as an important development area. The results and recommendations from these two projects were the basis for this project. A pan-european surveillance system using primary care networks already exists for influenza. 4 The European Influenza Surveillance Scheme (EISS) began in 1995 with the participation of seven countries: Belgium, France, Germany, the Netherlands, Portugal, Spain and the United Kingdom. The clinical surveillance of influenza is based on reports from GPs in primary care networks. There are many reasons why influenza surveillance networks in Europe have got together to share information. Influenza is a communicable disease that spreads rapidly and efficiently; this means that it is very beneficial for countries to be informed about influenza activity in neighbouring countries (clinical incidences and types/subtypes/strains). Other benefits of working together are that surveillance systems can learn from each other and improve their surveillance activities. Collaboration also helps the creation and development of disease surveillance networks across the whole of Europe.!"$#%&('*) +,+- 9

3URMHFWDLPV The project seeks primarily to contribute to the European Union Public Health Information Network / Health Indicators Exchange and Monitoring System (EUPHIN/HIEMS). The project aim is to study the feasibility of providing epidemiological information on health indicators. Data will be derived from routine primary care delivery for diseases that are exclusively or predominantly managed in primary care. Health Indicator Profiles (HIP) will be developed that help to clarify the appropriateness of primary care as source of epidemiological information. A second aim of these profiles will be to provide information on the validity and international comparability of information from primary care. This will allow adequate interpretation of the information and enable valid comparisons between countries. Moreover an attempt will be made to extend the project activities to EU member states which so far have not been able to deliver these epidemiological data. 3DUWLFLSDQWVDQGPHHWLQJV The project was carried out at the Netherlands Institute for Health Services Research (NIVEL) by Joan Deckers (researcher) and François Schellevis (project leader). The European primary care networks had the following representatives taking part in the project: œ Aad Bartelds (Continue Morbiditeits Registratie Peilstations, NIVEL, Utrecht, the Netherlands) œ Nathalie Bossuyt (Belgisch network van Huisartsenpeilpraktijken, Scientific Institute for Public Health, Brussels, Belgium) œ Jean-Marie Cohen (Open Rome, Paris, France) œ Isabel Falcao (Médicos-Sentinela, Instituto Nacional da Saude, Lisbon, Portugal) œ Antoine Flahault (Réseau Sentinelles, Inserm, Paris, France) œ Douglas Fleming (Weekly Returns Service, Birmingham Research Unit of Royal College of General Practitioners, Birmingham, United Kingdom) œ Anja Frenzen (Sächsischen epidemiologischen Studie in der Allgemeinmedizin (SESAM) III, Leipzig University, Leipzig, Germany) œ Jean-Luc Gallais (Observatoire de la Médecine Générale (OMG) de la Société Française de Médecine Générale (SFMG), Issy les Moulineaux, France) œ Hagen Sandholzer (SESAM III, Leipzig University, Leipzig, Germany) œ Viviane van Casteren (Belgisch network van Huisartsenpeilpraktijken, Scientific Institute for Public Health, Brussels, Belgium) œ Tomas Vega Alonso (Red de Médicos Centinelas de Castilla y León, Dirección General de Salud Pública y Consumo, Valladolid, Spain) on behalf of the regional Spanish primary care networks. A total of five meetings was organised in which the progress of the project was discussed. These meetings took place on 22-23 February 2002 (Utrecht, NL), 21-22 June 2002 10!"$#%&('*) +,+-

(Paris, FR), 13-14 March 2003 (Utrecht, NL), 30 September-1 October 2003 (Valladolid, ES) and 12-13 February 2003 (Brussels, BE). The meeting minutes can be found in appendix A. 2YHUYLHZRIWKHUHSRUW One of the aims of the European Public Health Programme is to collect information on health status in the individual Member States and to make this information on a European level available to the individual Member States. To achieve this, a set of European Community Health Indicators has been established. In general, an indicator needs to be valid (i.e. measure what one thinks it measures), be sensitive to changes over time and be comparable between countries and regions. Disease-specific morbidity at the population level is one of the areas of interest. This report studies the feasibility of routinely collected data from primary care as an information source for these health indicators. When using morbidity data as indicator for (differences in) health status between countries, it is important that the actual data are valid and comparable. Differences in operation and recording by the networks, and differences in health systems affect the validity and comparability of morbidity data from primary care. We therefore start with a description of the structure and operation of various primary care based registration networks in Europe (Chapter 2), to explore whether methodological issues can account for observed differences. We continue with a discussion of the primary care situation in the participating countries in chapter 3, to see to what extent variation in health systems may affect the results. We then present health indicator profiles, a tool for international comparison of health data (Chapter 4). The profiles represent a structured approach for international comparisons. These profiles are applied in chapter 5 in which primary care data for eight diseases from various networks are compared. Finally, we give recommendations and conclusions for the use of primary care data in European perspective in chapter 6.!"$#%&('*) +,+- 11

12!"$#%&('*) +,+-

'HVFULSWLRQRISULPDU\FDUHUHJLVWUDWLRQQHWZRUNV 6XPPDU\ In many European countries, primary care practice networks are in place and play a major role in public health surveillance. These networks are organised and function in varying ways. Information from them is one of the potential sources for a European health information and monitoring system which is envisaged in the European Public Health Programme. However, a detailed description of each data source is a prerequisite to ensure the validity and quality of the data and the validity of comparisons. In a previous project, an inventory was made of functioning primary care networks collecting morbidity data on a continuous basis, according to the definition: µ$qhwzrunrisudfwlfhvrufrppxqlw\edvhgsulpdu\fduh SK\VLFLDQVZKRPRQLWRURQHRUPRUHVSHFLILFLOOQHVVSUREOHPVRQDUHJXODUDQGFRQWLQXLQJEDVLV. Site visits were made to those networks cooperating in the current project which delivered epidemiological information. A standardised questionnaire was used to investigate aspects of function and recording quality. Eight primary care networks in Belgium, England & Wales, France (two networks), Germany, the Netherlands, Portugal and Spain delivered basic epidemiological information (case definition, numerator/denominator stratified for gender and age groups) on diseases mainly managed in primary care. Most of these networks are funded by their respective Ministries of Health, some others by governmental research funds. In general, the networks comprise a stable group of general practitioners (GPs) and monitor a representative sample of the general population (either at regional or national level). Some networks monitor all diagnoses presented and others a limited selection of diseases. Many of the networks use disease-specific questionnaires to provide enhanced data on selected diseases for specific purposes. The frequency of reporting by the central organisation of the networks varies from daily to annually. Primary care surveillance networks are an important tool for public health surveillance in Europe (particularly for, but not restricted to infectious diseases). Organisations running a primary care network can learn from networks in other countries and where necessary improve their own functioning. When all networks fulfil identical minimal criteria these networks can provide comparable estimates of morbidity attributed to certain diseases and this will ultimately lead to improved surveillance nationally and internationally. %DFNJURXQG The health of the population is a major concern for every national government. International comparisons help us to understand the reason for apparent national differences. Reliable and continuing information on health (and health related problems) and on the prevalence and incidence of disease are paramount. This information need is the basis for national surveillance-systems. Several sources of data are available: for example mortality statistics, hospital discharge registers, disease-specific registers, notification registers, prescription databases. However, no data source is totally comprehensive and all data sources provide information, limited to the purpose for which!"$#%&('*) +,+- 13

each was established. Many conditions do not lead to hospital admission or death but have a great impact on the health and wellbeing of the population and on national economies Data from primary care and health interview and health examination surveys (HIS/HES) are needed to inform on these. Primary care is often the entry-point into the health care system and the majority of health problems are managed exclusively in primary care. Therefore primary care based registration networks delivering reliable data in a consistent manner are potentially an important source of public health information. Moreover, primary care is the first and nearest source of medical information to the general population. In comparison to information obtained in HIS, data from primary care have the added advantage of professional assessment being described by the doctor rather than the patient. From an epidemiological point of view, although sometimes problematic, the epidemiological denominator can be defined more easily than in secondary health care facilities. In countries where universal patient registration with a primary care practice is usual, characteristics of the denominator population are readily available. Primary care networks are composed of a sample of general practitioners who report the occurrence of (a group of selected) diseases to a central office. These networks were often originally established to enable practitioners to engage in research and comprised willing and motivated volunteers. Nowadays the systems commonly provide data on infectious diseases, particularly vaccine preventable infections. Participating practices are called sentinel practices, with the implication of acting as a guardian or warning information system for the whole population in respect of the morbidity encountered. A distinction between surveillance and monitoring has to be made. Surveillance is actively observing incidence of diseases either in the short term (early warning) or long term (time trends). Monitoring is more passively surveying the health of a population. In general surveillance is focused on communicable diseases whereas monitoring is mainly concerned with chronic conditions. 3XUSRVH In the previous project an inventory of primary care registration networks was performed using the following definition: µ$qhwzrunrisudfwlfhvrufrppxqlw\edvhgsulpdu\fduh SK\VLFLDQVZKRPRQLWRURQHRUPRUHVSHFLILFLOOQHVVSUREOHPVRQDUHJXODUDQG FRQWLQXLQJEDVLV 2 In order to receive more background information on the networks and to facilitate international comparison of the information provided by the networks, site visits have been performed. These visits are also important for establishing the quality of these networks and hence the validity of the information provided. Site visits were conducted to provide a consistent description of each network and to clarify details of their functioning. A standardised questionnaire was used. We hoped to define minimal structural and recording conditions for a successful network. By providing feedback information to the participating networks we hoped to stimulate improvements in the networks; we can all learn from the experience of others. In 14!"$#%&('*) +,+-

particular procedures for quality control developed in one network can be applied elsewhere. The concept of a minimum standard could be seen as a pre-requisite for using the data to describe trends and to make national comparisons. 0HWKRGV Site visits were performed in eight primary care networks. The site visits consisted of a visit to one participating GP and to the central organisation. Both completed a standardised questionnaire before the visit and another standardised questionnaire was used at the actual visit (see Appendix B). The pre-visit questionnaire for the central organisation consisted of the following topics: 1 background information on network and its organisation, 2 operational organisation, 3 data collection, 4 use of data 5 a brief description of the health care system. The actual site visit included the following topics: 1 data transmission and data entry, 2 data storage, 3 data analysis, 4 questions based upon pre-visit questionnaire 5 additional comments. The pre-visit practice questionnaire concerned practice information on recording procedures, data summary/analysis, data transmission, support from network organisation and additional comments. During the site visit to the sentinel GP basic information on the practice, on the sentinel activities of the practice, operational information and personal comments were observed and collected. )LQGLQJV %DFNJURXQGLQIRUPDWLRQRQQHWZRUNDQGRUJDQLVDWLRQ A summarising overview of all findings can be found in appendix B (Table B1). The original site visit reports are also in Appendix B. All networks, except the German one in Saxony, have existed for more than ten years. The year of establishment varied from 1964 to 1996. Despite this variation, the aims of the networks were similar, all providing information on morbidity encountered in primary care. Funding generally came from government and university budgets, though the two French networks also received money from the private sector. Diseases were recorded in a continuous manner (this was a prerequisite to join the project). The number of diseases surveyed varied from a selection (usually between 5 and 10) to comprehensive recording of all GP contacts. All organisations had scientific and administrative personnel and most also technical. The number of personnel involved in managing the network varied from 0.9 in the Netherlands to 6.8!"$#%&('*) +,+- 15

full-time equivalents (fte) in France (SFMG). In Belgium, the Netherlands and England & Wales participating GPs receive financial compensation, in the other countries there was no compensation except for the conduct of special studies (France Inserm) or when given as technical support (Castilla & Léon, Portugal). The population monitored varied from 0.5% to 5% of the national or regional population. Most networks were representative for age, gender and geographical distribution but in some, representativeness was assumed without supporting evidence. The representativeness of the population is a critical issue. Representativeness for age and sex can be assumed in most countries, however information on other health-determining factors like socio-economic status or ethnic origin are not readily available. Where networks report on GP-interventions there is also a need to consider the representativeness of the GPs. However studies of representativeness require resources and funding that are not routinely available in sentinel networks. 2SHUDWLRQDOLQIRUPDWLRQ The median number of participating GPs in the national networks was 170 (range 65-1300). In France Inserm there were 1300 registered participants of which on average 150 participate in weekly surveillance. In most cases the minimum number of participants was determined by the number needed to guarantee national coverage. In the Spanish region of Castilla & Léon a maximum number of participants was defined based upon adequate operational control and cost-effectiveness. Some networks organise training courses on recording, use of software or research methodology. In others this is limited to an annual (written) instruction for recording. Where relevant comparisons could be made, (for example by age, gender, size of practice) participating GPs were often not representative of the national GP population. Participating GPs are willing to spend extra time for public health surveillance which is not always financially compensated, which inevitably leads to selective bias in the recruitment of well motivated practices. Though motivation may bias attitudes, it is unlikely to influence recording behaviour. The requirements for GPs to join networks were mostly based upon the maintenance of representative coverage. In France (Open Rome/SFMG) and England & Wales another requirement was compatibility of software packages with the central system. The turnover of the networks was limited to 5%. Compliance of GPs was defined differently in each network. In most networks a minimum participation rate exists, if participants report less than this defined number of days or weeks, their data were not included in the analysis. Overall the majority of the GPs reported on a regular basis. Feedback to participants consisted of newsletters, annual reports and meetings. In some countries GPs received each year an overview consisting of their individual results in relation to the results from the whole network. In Spain and France internet was also used as a means of discussion and information. Communication between participants within the networks was unusual. 'DWDFROOHFWLRQDQGDQDO\VLV Data collection was performed either by standardised paper forms (Belgium, Germany, Spain, the Netherlands and Portugal) or electronically. For electronic data collection 16!"$#%&('*) +,+-

standardised extractions from electronic medical records (France Open Rome/SFMG, England & Wales) or standardised forms on internet (France Inserm) were used. In most countries there were several software packages for electronic medical records, presenting organisational problems for automated recording. Networks need specific extraction software for each of the existing electronic medical record packages. Updating the extraction programmes requires staff and financial resources. This is an important issue for countries considering the transition from a paper system to a electronic system. The minimum data set in all countries consisted of GP and/or patient ID, diagnosis, age and gender of patient. In some countries the number of patient contacts, number of days recorded, week number or date were also collected to calculate or estimate the denominator. A case definition to classify the diagnosis was used when possible, but this varied with the topic. Data from paper forms were entered by administrative staff at the respective institutes. In Germany the textual information on the diagnosis or reason for encounter was recoded in international classification of disease (ICD)-10 resp. international classification of primary care (ICPC) by three independent GPs. For electronic data collection transfer occurred automatically on a daily to monthly basis. Information was stored in various types of databases which either contained all information in one file or in separate files per disease and/or year. Where possible, missing data were followed up and when not corrected excluded from the analysis. The frequency of reporting by the GPs to the central database is generally weekly, except for France (Open Rome/SFMG) and Germany where it was monthly or quarterly and England & Wales where it was twice weekly. There were a number of quality control measures in place in the various networks, an overview of possible measures is shown in Figure 2.1. Paper forms were visually inspected, consistency checks were incorporated in the data-entry programmes and double data entry was applied. Preliminary analyses were performed to compare data to expected figures or national averages. Furthermore data samples were used for interobserver reliability testing. Potential external validation sources are for instance mortality statistics, disease registers or prescription data.!"$#%&('*) +,+- 17

Figure 2.1 Possible quality measures in primary care registration networks *3 75$16)(5 &225',1$7,21&(175( - Coding: - Security: - Inconsistencies: - Reliability - Passwords - Age - Inter-observer testing - Double entries - Sex - Case definition - Privacy (patients) - Total number (tolerance matrix) - Pilot study (for recording) - Confirmation of receipt - Data entry (limited codes) - Practice visits - Double data entry - Training - Corrections - Feedback: - Publications - Results - External validation - Bulletin - Meeting questionnaire - Diagnosis verification (by lab) - Completeness of diagnosis - Privacy aspects (patients) - Representativeness However, the basic and determining quality of primary care networks is the quality of the diagnosis made by the GPs. If influencing the diagnosis is at all possible it is certainly very expensive. The costs of investigating the diagnostic validity of common self-limiting illnesses are often not justifiable. Therefore, control measures to check for correct use of diagnoses are not applied. In contrast, many efforts are made to validate the information on the level of the entire network, e.g. by comparing this with other information sources. In general, the absolute number of patients is expressed as relative frequency of disease per 10,000 or 100,000 persons. In some cases standardisation for age and sex to the national population is also performed. As explained before, GPs who do not record on a regular basis (defined as < 50% in most cases) are excluded from the analyses. As a routine, the incidence or prevalence per 10,000 or 100,000 persons by age and gender is determined by scientific and technical staff. Those networks that record a selection of diseases often collect additional information about specific diseases on an ad hoc basis; for example description of symptoms, follow-up, referral to other health care professionals and prescribing information. This information was analysed on a case by case basis. Annual analyses are performed routinely in all networks. Some analyse more regularly, in England & Wales twice weekly, in France (Inserm) weekly, and in the Spanish region of Castilla & Léon quarterly. The only exception concerns the surveillance of influenza-like-illness which during winter is analysed on a weekly basis everywhere. Problems encountered in the process of data collection, transfer and analysis included incompleteness of data, technical problems with software packages and dataretrieval, discontinuation of recording by GPs because of a high workload, limited staff resources leading to delays in analysis and publications. 18!"$#%&('*) +,+-

)XWXUHRISULPDU\FDUHQHWZRUNV An important issue to consider is the future of primary care networks in general and in the context of the future European Health Information System. How will the current networks be functioning in 5 to 10 years time? The views of the individual networks can be found in Appendix A (meeting minutes for the 3rd meeting, 13-14 March 2003). Currently all networks monitor and report on morbidity in the general practice population. It is thought that in the future paper forms will no longer be used. Most networks will switch to automated recording and are likely to expand to comprehensive recording of all morbidity, although some networks expressed a preference only to analyse selected diseases. Monitoring selected diseases has the advantage of the possibility of collecting additional information on diagnosis and management. On the other hand, comprehensive recording allows an overview of all GP contacts and provides added context especially with regard to prescribing information and referral behaviour. However specific details about individual problems are less readily available. A clear-cut answer to the question which is the best system cannot be given, though the precise purpose of the network will often determine the answer. Switching to automated data collection also means that the frequency of reporting can be increased to weekly or even daily. Cooperation with laboratories and other health care professionals and research institutes, is an issue foreseen by most participants. All these changes are largely determined by funding arrangements. For most networks funding is secure for 2-3 years, even though most of the networks have existed for more than ten years. However it is necessary to implement changes (comprehensive recording and automated data collection) to maintain primary care networks as an important source of health information to support health policy and public health surveillance. To guarantee adequate monitoring and development of the systems continuous financial support is required. Excessive funding however might exert an influence on the recording of diagnoses. It would seem undesirable for funding to come from a source with a vested interest in specific aspects of the data, e.g. prescribing. The participants in Belgium, the Netherlands and England & Wales are currently financially compensated at a low level which does not cover the recording costs. In the Spanish region of Castilla & Léon and in Portugal compensation is given in the form of technical support. Financial compensation for the GPs gives the network organisers greater scope to dismiss poor recorders and generally to control the quality of recording. &RQFOXVLRQ Primary care surveillance networks are an important tool for public health surveillance in Europe. Although some networks are limited to the surveillance of infectious diseases, primary care networks are a useful source of information on health-related problems in general and not only morbidity. At first sight there seems to be wide variation in the operation of these networks. From the programme of site visits we consider the differences limited. The networks are either part of the respective national health service authorities or funded by them. Although they differ in size, most networks cover a!"$#%&('*) +,+- 19

representative sample of the population. Participating GPs are interested in public health and very few discontinue recording. All networks produce an annual report containing their findings and report more frequently as appropriate to the public health issue concerned. In our opinion, organisations running a primary care network can learn from networks in other countries and where necessary improve their own. Minimal criteria and operational standards need to be defined for inclusion of data from networks in a national and European information system. These include: œ FRQWLQXRXVVXUYHLOODQFH of a representative sample (around 1%) of the population œ representativeness of the SRSXODWLRQE\DJHDQGVH[ œ the use of VWDQGDUGDJHJURXSV with break points at 0-5-15-45-65 years. Additional breakpoints at 25 and 75 years are highly recommended. œ a registered patient list is preferred for determination of the GHQRPLQDWRU, although methods can be developed to make good estimates. œ ability to GHOLYHULQIRUPDWLRQ on a WLPHO\ basis. For surveillance of infectious diseases and diseases with a high seasonal influence reporting by the network is preferred to be on a weekly basis. For other conditions annual feedback suffices. œ TXDOLW\FRQWURO measures, although time-consuming and therefore costly, must be in place to ensure reliable and valid data. One option that needs further study is the development of methods to verify the completeness and representativeness of the data exploiting inconsistencies within the data. For the future the move towards comprehensive recording and automated data collection is desirable. However to implement these changes and to guarantee adequate monitoring continuous financial support is essential. 20!"$#%&('*) +,+-