Attending the Diabetes Center Is Associated With Increased 5-Year Survival Probability of Diabetic Patients: The Verona Diabetes Study

Abstract

OBJECTIVE The aim of the present study is to compare the survival of patients attending diabetes centers with that of patients exclusively consulting family physicians. RESEARCH DESIGN AND METHODS The study was carried out in the frame of the Verona Diabetes Study, a population-based survey of known diabetes prevalence with a subsequent 5-year mortality follow-up. A cohort of 7,488 diabetic patients were identified on 31 December 1986 from three different sources: a drug consumption database, family physicians, and diabetes centers (one for children and one for adults). As of 31 December 1986, 3,288 patients in the entire cohort exclusively consulted their own family physicians, while 4,200 patients also had periodic examinations at the diabetes centers. The life status of the diabetic cohort was ascertained on 31 December 1991. RESULTS Compared with the nondiabetic population, diabetic patients seen only by family physicians had a standardized mortality ratio (SMR) of 1.62 (95% CI 1.51–1.74), while patients attending both family physicians and diabetes centers showed an SMR of 1.44 (1.34–1.54), the difference being statistically significant (P = 0.017). The 5-year survival probability, estimated by the Kaplan-Meier method, was 0.76 (0.75–0.78) in patients seen only by family physicians and 0.81 (0.80–0.82) in patients attending the diabetes centers. Multivariate analysis by Cox regression model showed that attending the diabetes centers was an independent predictor of survival even after adjusting for sex, age, and therapy of diabetes. The relative risk of 5-year all-cause mortality amounted to 0.83 (0.75–0.92) in patients also attending the diabetes centers with respect to patients consulting only family physicians (P < 0.001). CONCLUSIONS These data on patients' survival indicate that diabetes centers play a crucial role in diabetes care. As a corollary, an integration between primary-care physicians and diabetes centers is strongly recommended.