Abstract
Background
Diabetic retinopathy (DR) is emerging as a global public health issue that may result in visual impairment. It has become the leading cause of blindness among working-age adults globally, despite established treatments that can reduce the risk by 60%. Disease progression, as indicated by longitudinal HbA1c measurements, may affect the time of interest (retinopathy). Hence, poor glycemic control increases and hastens the risk of retinopathy.
Objective
This study aimed to determine the incidence of diabetic retinopathy and its predictors among adult diabetic patients in public hospitals in Central and Southern Ethiopia.
Methods
A retrospective follow-up study was conducted at selected hospitals in Central and Southern Ethiopia among newly diagnosed patients with adult diabetes between January 1, 2015, and June 30, 2022. A systematic random sampling technique was applied. The data were collected and entered into Epi-data version 4.6.0.2 and exported to STATA version 14 for analysis. Descriptive statistics of the variables were obtained. The Cox proportional hazard assumption was checked. The Cox regression model was used to quantify the effects of covariates on the time to diabetic retinopathy. A p value less than 0.25 was the cut-off point for selecting variables for the bivariable analysis and candidates for the final analysis. In the multivariable analysis, variables with a p value less than 0.05 and a corresponding 95% confidence interval in the final model were used. Model adequacy was checked.
Results
A total of 376 adult diabetic patients were followed for 45752 person-months. Overall, 96 (25.5%) patients developed diabetic retinopathy, with an incidence rate of 11.7 per 1000 person-months of observation. Positive proteinuria (AHR = 2.19: 95% CI: 1.18, 4.08), hypertension (Yes) (AHR = 2.23: 95% CI: 1.39, 3.55) and type II DM (AHR = 2.89: 95% CI: 1.19, 7.05) were identified as significant predictors of diabetic retinopathy.
Conclusion
The incidence rate of diabetic retinopathy was high. Hypertension, proteinuria and type of diabetes were identified as predictors of diabetic retinopathy. Aggressive management should be implemented, and DM patients with hypertension and positive proteinuria should be followed to optimize positive outcomes.