Prevalence of known diabetes mellitus in a central region of Italy

A survey on the prevalence of known diabetes mellitus has been conducted in the Foligno area, in the region of Umbria in central Italy, using the capture-recapture method. Three independent sources of information were used to obtain the most reliable and complete data. In 1990, the number of people registered with the National Health Services in the Foligno area was 92,196. A total of 2908 subjects with known diabetes were identified (crude prevalence of diabetes was 3.15%). The diabetic population was distributed between 0.08% for Type I and 3.1% for Type II diabetes. Out of 2908 patients identified by the 3 sources of information utilized, 1092 were traced in general practitioners' and paediatricians' registries, 1653 in diabetic clinic registries and 2101 from prescriptions for hypoglycaemic agents, insulin syringes or reagent strips. The applications of the capture-recapture methodology led to an estimated prevalence of diabetes mellitus in the Foligno Health Care District of 3.18% (95% CI: 3.17%-3.19%). This survey allowed the identification of about 99% of the diabetic population. Knowledge of the data referring to other areas in Italy and in European countries could help to evaluate the possible differences between the various Italian regions and other European countries. The next step should be a survey to obtain data on the prevalence of chronic diabetic complications on which life expectancy depends.