A PREVALENCE STUDY OF KNOWN DIABETES-MELLITUS IN TUSCANY ASSESSED FROM PHARMACEUTICAL PRESCRIPTIONS AND OTHER INDEPENDENT SOURCES

This study evaluates the prevalence of diabetes mellitus (DM) in Pisa (Tuscany, Italy) using four independent data sources. The main source, represented by computerized prescriptions for anti-diabetic agents co llected over a 4-month period, was validated using three secondary sou rces: (a) the list of diabetic patients who receive material of self-c are from the National Health Service; (b) the clinical records of diab etic patients obtained from a random sample of family doctors; (c) the clinical records of diabetic patients attending our outpatient clinic . The main source provided 3806 patients, and 697 patients were added from the secondary sources, thus identifying a total number of 4503. T he prevalence of known DM in the ''Pisa area'' exclusively reckoned by the main source, was 2.01%, and the prevalence corrected by the addit ion of the various sources resulted in 2.4%. The capture-recapture met hod showed a completeness of ascertainment of the survey of 90.1%, and thus an estimated prevalence of known diabetes Of 2.64%. Of these, 14 1 patients had insulin-dependent diabetes mellitus (IDDM) correspondin g to 3.2% of identified diabetic subjects (prevalence 0.07% inhabitant s); 4362 patients had non-insulin-dependent diabetes mellitus (NIDDM), 96.8% of identified diabetic subjects (prevalence 2.36%). Of patients with NIDDM 10.5% was treated by diet, 65% with oral hypoglycaemic age nts (OHA), 23% with insulin and 1.5% with insulin plus OHA. This study shows that the method used in this survey is suitable for epidemiolog ical studies because it does not demand the cooperation of the diabeti c patients, is addressed to the entire diabetic population without age discrimination and singles out the diabetic population in a very reli able way.