Hospitalization of patients with diabetes.

To determine annual hospitalization rates for patients with diabetes mellitus, we retrospectively analyzed the frequency of hospitalization among 905 patients with diabetes receiving primary care in a private practice outpatient program during a 20-month period (1,508 patient-years). We assessed the annual hospitalization rates stratified by diabetes clinical severity index, type of diabetes, type of treatment, age, sex, and mean glycosylated hemoglobin. The all-cause annual hospitalization rate was 211 per 1,000 patients (95% confidence interval, 184 to 238). Hospitalization rates were strongly correlated with measures of clinical severity; hospitalization rates did not vary significantly with type of diabetes, age, or sex. Among patients with type II diabetes, rates were higher in the group treated with insulin. A trend was noted for hospitalization rates to increase with mean glycosylated hemoglobin (not statistically significant in this sample). Overall, 14% of hospitalizations were for metabolic reasons, 45% were related to clinical complications of diabetes, and 41% were unrelated to the presence of diabetes. In analysis of hospitalization rates and therefore health-care expenditures for patients with diabetes, the characteristics of the patient population--and especially measures of clinical severity--must be considered. Interventions to reduce hospitalization can be targeted at high-risk groups.