Health-related quality of life associated with diabetic retinopathy in patients at a public primary care service in southern Brazil

Objective: This study aimed to establish the utility values of different health states associated with diabetic retinopathy in a Brazilian sample to provide input to model-based economic evaluations. Subjects and methods: This cross-sectional study was performed in a sample of patients with type 2 diabetes mellitus (T2D) who underwent teleophthalmology screening at a primary care service from 2014 to 2016. Five diabetic retinopathy health states were defined: absent, non-sight-threatening, sight-threatening, and bilateral blindness. Utility values were estimated using the Brazilian EuroQol five dimensions (EQ-5D) tariffs. Descriptive statistics were calculated. Analysis of covariance was performed to adjust the utility values for potential confounders. Results: The study included 206 patients.The mean (+/- standard deviation [SD]) utility value was 0.765 +/- 0.19 (95% confidence interval [CI], 0.740-0.790).The adjusted mean utility value was 0.748 (95% CI, 0.698-0.798) in patients without diabetic retinopathy, 0.752 (95% CI, 0.679-0.825) in those with non-sight-threatening state, 0.628 (95% CI, 0.521-0.736) in those with sight-threatening state, and 0.355 (95% CI, 0.105-0.606) in those with bilateral blindness. A significant utility decrement was found between patients without diabetic retinopathy and those with a sight-threatening health state (0.748 vs. 0.628, respectively, p= 0.04). Conclusions: The findings suggest that a later diabetic retinopathy health state is associated with a decrement in utility value compared with the absence of retinopathy in patients with T2D. The results may be useful as preliminary input to model-based economic evaluations. Further research is needed to investigate the impact of diabetic retinopathy on health-related quality of life in a sample more representative of the Brazilian population.