Time to Diabetic Nephropathy and its Predictors Among Diabetic Patients Treated in Wolaita and Dawuro Zone Hospitals, Ethiopia: A Retrospective Cohort Study.

Background: Diabetic kidney disease (DKD) develops in nearly half of patients with type 2 diabetes mellitus (DM) and one-third of those with type 1 DM during their lifetime. The incidence of DKD as a cause of end stage renal disease is increasing each year. So this study aimed to assess the time to develop diabetic nephropathy and predictors among diabetic patients treated in Wolaita zone hospitals. Methodology: A ten-year retrospective cohort study had conducted among 614 diabetic patients using systematic random sampling in Wolaita and Dawuro zone hospitals. Bivariable and multivariable Cox proportional hazards regression had used to identify the possible associations between variables. Those variables with a p-value of less than 0.25 in bivariable analysis exported to multivariable Cox regression analysis. Finally, variables with p-value less than 0.05 at multivariable Cox regression were considered significantly significant. The Cox-proportional hazard model assumption had checked using the Schoenfeld residual test. Results: Of the total participants, 93 (15.3%; 95% CI = 12.45-18.14) patients had developed nephropathy in 820,048 people year observation. A mean time to diabetic nephropathy in this study was 189.63 (95% CI, 185.01, 194.25) months. Being illiterate (AHR: 2.21, 95% CI: 1.34-3.66), being hypertensive (AHR: 5.76, 95% CI: 3.39-9.59), and being urban dwellers (AHR: 2.25, 95% CI: 1.34-3.77) increases the hazard of nephropathy. Conclusion: According to this follow-up study, the overall incidence rate is substantially high over ten year follow-up period. The mean time to develop diabetic nephropathy was sixteen years. Educational status, place of residence, and being hypertensive were the predictors. So stakeholders should work on complication reduction measures and awareness creation of the impact of comorbidities.