Training supervision and presence of at least one pharmacy in the municipality were the only factors associated with a favourable evolution of the density of GPs in this 3-year follow-up study. Multivariate analysis found several other factors associated with a negative evolution of medical density. These factors had already been identified in the literature, such as rural territories , advanced age of doctors retiring earlier and existence of a significant basic medical density on the territory .
It should be noted that the proportion of women was associated with an unfavourable evolution in multivariate analysis, whereas it was related to a favourable evolution in bivariate analysis. The authors believe that this surprising result is due to a very unequal distribution of women in the population age pyramid.
Financial aid for installation was associated with an unfavourable evolution in bivariate analysis, but this relationship disappeared in multivariate analysis. This result is likely associated with a correlation between financial aid and rural territories. The latter is known to be associated with an unfavourable evolution of the density of GPs and it was confirmed in our work. It is interesting to note that a financial aid failed to counterbalance this effect. Since this grant is recent, we suggest that a follow-up is too short to bring out an effect on demography in our study.
The relationship between a favourable evolution of medical density and existence of multiprofessional practices disappeared in multivariate analysis. While group exercise is a favourable element in recruiting and keeping health professionals in a territory , we believe that this result is due to a relationship between presence of multiprofessional practices and density of TS in municipalities .
The relationship between presence of TS and favourable evolution of medical demography was highlighted by a significant coefficient in a cohort with only 3 years of follow-up. These elements tend to indicate the attractive feature of TS in their territory. However, this work only studied the effect of TS on their municipality of practice. It does not consider installations on the outskirts of their location of practice, which would have been a more relevant territorial unit to analyse the evolution of medical demography. Unfortunately, this choice was not possible for the methodological reasons mentioned above, but several studies suggest that new doctors also settle in neighbouring territories.
The issue of causality remains central. Do TS improve the attractiveness of their territory or is it the territory that is attractive? This work cannot formally answer this question. To do so, a randomised interventional study would be required, but it is not possible with the actual lack of TS. However, the multivariate analysis carried out in this work, although it could not integrate all the factors associated with the evolution of medical demography, found a persistent relationship between training supervision and favourable evolution of the density of GPs across the country. In addition, in a study of 2009, TS did not seem to be installed in different areas than other GPs in terms of access to care . This study suggests the existence of a specific effect of TS on medical demography.
Strengths and limitations
Several international studies have analysed the factors explaining the attractiveness of municipalities with the difficulty of comparing different health systems. Until now, no cohort studies evaluated training supervision. The collection of a pool of TS directly conducted by the general practice departments ensured the reliability of the data about the numbers and locations of TS. This cohort study covers almost the entire French territory, which improves its validity.
However, there are several limitations to consider. First, this work does not take into account the evolution of GPs in cities that were not endowed in 2018. A total of 255 municipalities are in this situation and the authors believe that their number is negligible on the results of this work. Moreover, this work does not consider the TS who stopped and those who started their activity between 2018 and 2021. Their number grew by 17.2%, or 1.624 more TS over this period [18, 24]. The effect of these TS has not been considered. We believe that GPs who started their TS activity after the beginning of the follow-up did not have enough time to have an impact on the attractiveness of their territory and that their effect can be neglected. Several elements which probably had an impact on the attractiveness of TS, such as their seniority and the length of time they received students, were unavailable for this database and could not be analysed. The financial aid analysed in this work correspond to the current national support. Local financial aids sometimes proposed by some areas could not be considered.
The evolution of medical demography is a major concern for the coming years. In France, as elsewhere, it is relevant not to limit the issue of distribution of GPs to the number of trained GPs . The influence of TS on the medical demography of their territory could constitute a simple and effective response to the problems of access to care. This impact could improve support for the deployment of TS in territories and, more generally, for considering an additional interest in primary care internships in the curriculum of general practice residents. The modest resources invested in recruitment, remuneration and education of training supervisors must be weighed against the considerable resources invested for the attractiveness of areas lacking of doctors, for which effects are still poorly known and limited in time .
Given the impact of the training supervision on medical demography, it would be consistent to value territories by the existence of TS.