Mortality and educational level among diabetic and non-diabetic population in the Turin Longitudinal Study: a 9-year follow-up

Background People in a lower social position have a higher prevalence of unhealthy behaviour, more difficult access to healthcare, and lower compliance with drug treatment; as a consequence, social differences in mortality are likely to be higher in people with diabetes compared with the non-diabetic population. We compared diabetics with non-diabetics in terms of mortality and social differences in mortality. Methods In all, 31 264 residents in Turin (northern Italy), who were greater than or equal to20 years old, registered in the local diabetes register between 1991 and 1999. They were followed up from recruitment to December 1999, and their cause-specific mortality by educational level was analysed. This was compared with that of the local non-diabetic population. Diabetes was classified as type 1 (less than or equal to35 years at diagnosis) or type 2 (>35 years). Results For type 1 diabetes, the all-cause standardized mortality ratio (SMR) was 197.6 (95% CI:155.7, 247.4) in men and 336.0 (95% CI:259.3, 428.2) in women; for type 2 diabetes, the all-cause SMR was 142.8 (95% CI:138, 147.6) in men and 143.4 (95% CI:138.5, 148.5) in women. Whereas social differences in mortality were evident among non-diabetic men and women for all causes of death considered, no significant differences were found among diabetic women. Mortality was slightly increased among less educated diabetic men, particularly for neoplasms, although this gradient was less steep than that among non-diabetics. Conclusions These results suggest that the regular clinical follow-up and health education provided by the local network of diabetic centres might play an important role in confronting the adverse effects of diabetes and in reducing social differences in health.