prises a network of sentinel general practitioners. (SGP). These benevolent volunteers are responsible for the weekly epidemiological surveillance. Since.
European Journal of Epidemiology 10: 477-479, 1994. © 1994 Kluwer Academic Publishers. Printed in the Netherlands
Constitution and monitoring of an epidemiological surveillance network with sentinel general practitioners Pierre Chauvin Unitd de Recherches Biomath~matiques et Biostatistiques, Paris, France
Abstract. The R6seau National T616-informatique de surveillance et d'information sur les Maladies Transmissibles (RNTMT) (French communicable diseases computerised surveillance network) comprises a network of sentinel general practitioners (SGP). These benevolent volunteers are responsible for the weekly epidemiological surveillance. Since its creation, t,700 SGPs have participated in the RNTMT, representing a total of more than 120,000 connections to the RNTMT telematic service center.
The principal motivation of these benevolent SGPs was to 'actively participate in public health', although only a minority of them (17.6%) had any training in this field. Such a system, based on the benevolent and voluntary activity of SGPs, requires a good understanding of SGPs' attitudes towards epidemiological surveillance in general and the tool used, in order to quantitatively and qualitatively follow their participation and to provide regular and useful feedback to the surveillance actors.
Key words: Epidemiological surveillance, General practitioners, Network
Introduction The constitution of a surveillance network with sentinel general practitioners (SGPs) may be considered from different points of view: recruiting SGPs (which presumes understanding of the GPs' knowledge and their interest and motivation in epidemiological surveillance), monitoring their participation in such a system (with the use of quality analysis tools), and providing them with useful and regular feedback. Since 1984, the R6seau National T616-informatique de surveillance et d'information sur les Maladies Transmissibles (RNTMT) has collected weekly data on seven communicable diseases, thanks to 500 voluntary and unpaid SGPs that represent 1% of all French GPs [1]. This experience will illustrate each of the above-mentioned steps.
The recruitment of SGPs Three objectives must be simultaneously accomplished. First, the target population must be reached (all the GPs in such a system), which demands a large dissemination of results and calls for participation. In France, we use the medical daily newspapers and the RNTMT bulletin, 'SENTINELLES', which is mailed to the 50,000 French GPs and to a number of specialists and public health institutions. Second, recruitment priorities must be selected in order to avoid the network's representation becoming dis-
torted by the turnover of SGPs, by using targeted recruitment procedures, especially in terms of regional distribution. Third, this overall turnover must be decreased, which means keeping the SGPs active without selecting 'surveillance professionals'; this can be achieved if the SGPs' motivations are known, if useful feedback is provided for them, and if collaboration with the SGPs in the choice of the objects of surveillance actually takes place.
The motivation of GPs regarding epidemiological surveillance Since 1992, all SGPs have been questioned regarding their motivation and attitudes towards epidemiological surveillance. The five main motives of SGPs for belonging to such a network are: to play a role in the area of public health (40%); a personal interest in epidemiology (25%); to get epidemiological feedback (17%); to have a rewarding function (10%); and to belong to a GP network (8%). Their interest in the surveillance of some communicable diseases has been investigated thanks to analog scales. SGPs are particularly concerned with the surveillance of diseases that are either rare and serious (tuberculosis, meningitis, AIDS), common with a well-known economic impact (influenza), subject to control measures (food-borne diseases, viral hepatitis, measles), or linked with sexual behaviour (viral hepatitis, AIDS, STDs) (cf. Figure 1).
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Figure 1. GPs' attitude towards the surveillance of some communicable diseases.
The monitoring of SGPs' participation The real participation of SGPs must be continuously monitored on two levels. Individual monitoring aims to increase the regularity of each SGP's work. In our system, the participation of a SGP is quantified as the number of actual surveillance days per week; if this participation is too low, a systematic and personal reminder operation (letter, fax or phone call) is activated. Global monitoring aims to correct the weekly fluctuation in our denominator and to produce estimated incidences [2]. The number of active SGPs is followed up weekly (Figure 2) and the % 80
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RNTMT database is re-weighed weekly on a regional level.
Quality analysis of SGPs' participation The recruitment of a GP is heavy work and, therefore, when a GP is joining the network, it would be useful to know if he is going to be a 'good' SGP. A criteria of this quality is his perseverance in the system. We are looking for objective individual variables which predispose a SGP to long perseverance, using survival analysis methods. Easter
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Figure 2. Weekly SGPs' participation, RNTMT, September 1992-September 1993.
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Figure 3. Kaplan Meyer survival curves of the SGPs according to their previous experiences in epidemiology, using a maximum time of silence authorised of 100 days. Source: RNTMT, September 1993. If an SGP's 'birthday' is the day of his first data supplying and his 'death', the first day followed by a silence I> T (where T is the maximum lapse of time authorised without any supplying of data), then his survival time is the time between these two dates. For instance, a GP who has taken part in a previous epidemiological study has a significantly longer survival time than one who has not (Figure 3); median survival times are respectively 3 years and 1 year for T = 100 days (p = 0.02). Several of the 40 individual variables can be investigated with the help of a Cox regression model to establish recruiting profiles.
data: increasing the SGPs' epidemiological knowledge without changing their medical practice, and monitoring their participation through systematic procedures without discouraging these volunteers. Modern techniques of market analysis, management and quality analysis are necessary to understand the motivation, attitudes and needs of GPs and to keep such a system working. These techniques guarantee that the work of the SGPs and the coordination staff will be as efficient as possible in providing reliable and useful public health data.
References Information and feedback Regular and useful feedback is an essential requirement to get good participation from the SGPs. In our network, the SGPs can read electronic bulletins, updated weekly, on their own videotex terminals (Minitel) [3]. They also receive a quarterly paper bulletin which sums up their own collected data and compares them to regional data. The surveillance results are regularly published in medical media and in the RNTMT bulletin, 'SENTINELLES'.
Conclusion Surveillance with GPs must reconcile opposing requirements in order to ensure the reliability of the
1. Valleron A-J, Garnerin P. Computer networking as a tool for public health surveillance: The French experiment. MMWR 1993; 41: 101-110. 2. Chauvin P, Diaz C, Garnerin P, et al. RNTMT : Bilan de la surveillance 6pid6miologique des m6decins sentinelles en 1992. Bull Epidemiol Hebd 1993; 21: 93-96. 3. Garnerin P, Saidi Y, Valleron A-J. The French Communicable Diseases Computer Network, a sevenyear experiment. Ann NY Acad Sci 1992; 670: 2942.
Address f o r correspondence: Dr Pierre Chauvin, Unit6 de
Recherches Biomath6matiqueset Biostatistiques, INSERM U263, Facult6 Saint Antoine, 27 rue de Chaligny, F-75571 Paris-12, France Phone: (1) 44 73 84 40; Fax: (1) 43 07 39 57
