A Cohort Study of Mortality in Two Clinic Populations of Patients with Diabetes Mellitus

Abstract

Mortality rates of two cohorts of patients with diabetes mellitus are estimated and compared. The Atlanta cohort is defined as all black patients receiving care at the diabetes clinic of Grady Memorial Hospital for the first time during calendar year 1971. The Memphis cohort is defined as all black patients referred from the City of Memphis Hospital outpatient clinic to a decentralized neighborhood clinic operated by the Memphis and Shelby County Health Department during September 1969 through August 1970. The Atlanta program discontinued all prescriptions of oral hypoglycemic drugs and emphasized instead an aggressive diet therapy. The Memphis program has used diet therapy but also insulin and/or oral hypoglycemic agents according to current guidelines. The ratios of observed to expected deaths (standardized mortality ratios) were remarkably similar for the two cohorts. In both cohorts the standardized mortality ratios were greatest for the youngest patients and for those patients whose duration of illness was longest. Nine-year survival rates, estimated by the life-table method and adjusted for differences in frequency distributions of entry age and duration of diabetes, were also similar for the two cohorts.