Mortality rates in diabetic patients from a community-based population compared to local age/sex matched controls

Using a population-based cohort from 10 general practices in East Dorset, the mortality rate of diabetic patients compared to non-diabetic controls was investigated during 8 years follow-up. From a total population of 90660, 917 diabetic patients were identified; 693 (75 %) with non-insulin-dependent (Type 2) diabetes and 224 (25 %) with insulin-dependent (Type 1) diabetes. A control group of 917 non-diabetic subjects were selected, matched by age and sex. After 8 years, significantly more diabetic patients (334 or 36.4 %) had died than controls (219 or 24 %), (odds ratio (OR) 1.99, 95 % CI 1.60–2.47). Compared with the controls, the odds ratio of all causes of mortality for diabetic men was 1.89 (CI 1.4–2.54) and for diabetic women 2.16 (CI 1.57–2.96). Compared with controls, the odds ratio for mortality from circulatory disease was significantly increased for diabetic patients 2.0 (CI 1.5–2.6) but mortality for respiratory disease or neoplasms was not significantly different (OR 0.7, CI 0.4–1.2 and OR 0.7, CI 0.6–1.0, respectively). Control data were lower than would be expected from national database data. The diabetic population had a significantly higher mortality than controls, both from all causes and circulatory diseases. Our data incidentally show the importance of appropriate controls for estimating the impact of a chronic disease. © 1997 by John Wiley & Sons, Ltd.