Influence of local structural factors on physicians' sick-listing practice:: a population-based study

Background: Physicians have a central role as gatekeepers to the social security system, including sick- listing. Variation in physicians' sick- listing practices has been demonstrated in several studies. The objective of this study was to determine whether local structural factors affect sick- listing practice. Methods: A total of 57 563 consecutive sick- listing certificates, issued during 4 months in 1995 and 2 months in 1996, were collected from the local branches of the National Social Insurance Office in eight Swedish counties. County code, local community population size and presence of a hospital in the area were used as indicators of local structural factors. Length of the sick- listing certificates and of the sick- listing episodes were used as outcome variables. Results: After ajustment for the influence of category of issuing physician, patients' age, sex and diagnosis (` case mix'), and type of certificate there was a large variation of the length of the sick- listing certificates and of the sick- listing episodes between counties, between communities of various size and between communities with or without a hospital in the area. All these factors were independently and significantly correlated to the length of the certificate and of the sick- listing episode. Conclusions: The results support the hypothesis that physicians' sick- listing practice is influenced by local structural factors.