Correlates of health-related quality of life in type 2 diabetes

Aims/hypothesis: We assessed the impact of medical comorbidities, depression, and treatment intensity on quality of life in a large primary care cohort of patients with type 2 diabetes. Methods: We used the Health Utilities Index-III, an instrument that measures health-related quality of life based on community preferences in units of health utility (scaled from 0=death to 1.0=perfect health), in 909 primary care patients with type 2 diabetes. Demographic and clinical correlates of health-related quality of life were assessed. Results: The median health utility score for this population was 0.70 (interquartile range 0.39-0.88). In univariate analyses, older age, female sex, low socioeconomic status, cardiovascular disease, microvascular complications, congestive heart failure, peripheral vascular disease, chronic lung disease, depression, insulin use and number of medications correlated with decreased quality of life, while obesity, hypertension and hypercholesterolaemia did not. In multiple regression analyses, microvascular complications, heart failure and depression were most strongly related to decreased health-related quality of life, independently of duration of diabetes; in these models, diabetes patients with depression had a utility of 0.59, while patients without symptomatic comorbidities did not have a significantly reduced quality of life. Treatment intensity remained a significant negative correlate of quality of life in multivariable models. Conclusions/interpretation: Patients with type 2 diabetes have a substantially decreased quality of life in association with symptomatic complications. The data suggest that treatment of depression and prevention of complications have the greatest potential to improve health-related quality of life in type 2 diabetes.