Time to Chronic Kidney Disease and Change in Blood Pressure among Hypertensive Patients, Northwest Ethiopia: A Bayesian Multivariate Joint Model

Abstract

Introduction: Hypertension is the second leading cause of Chronic Kidney Disease (CKD) worldwide. CKD is the severest form of kidney disease characterized by poor filtration rate. It is also the leading cause of morbidity and mortality in hypertensive patients. However, little is known about when this problem may occur, the predictors of time to chronic kidney disease, and its association with changes in blood pressure in hypertensive patients. Objectives: The aim of this study was to assess time to Chronic Kidney Disease and its predictors as well as its association with change in Blood Pressure among hypertensive patients in Ethiopia. Methods: A retrospective follow-up study was conducted among hypertensive patients at University of Gondar Comprehensive Specialized Referral Hospital, Northwest Ethiopia. A total of 433 newly diagnosed hypertension patients who had follow-up from 2014 to 2023 were selected using a computer-generated simple random sampling technique. The Cox Proportional Hazard and linear mixed effect models were fitted separately, and later, the models were fitted jointly using Bayesian approach by using R software, and 95% credible interval was used to select significant variables. Results: The incidence rate of CKD was 2.5 cases per 100 patients per year (95% CI [1.89-3.14]) with median follow-up time of 70 months [IQR, [43-97]. Current value of Systolic Blood Pressure and Diastolic Blood pressure were significantly associated with risk of CKD (AHR = 6.25; 95% CrI: [2.85 -9.85]) and (AHR = 4.32; 95% CrI: [2.35-8.27]) respectively. Age ≥ 65 years (AHR = 4.62; 95% CrI: [1.83, 12.21]), HDL_C <40 mg/dl (AHR = 3.32; 95% CrI: [1.73-7.86]), having Diabetes mellitus (AHR = 3.08; 95% CrI: [2.01-9.54]), and positive proteinuria (AHR = 2.85; 95% CrI: [1.48-5.55]) were significant predictors of time to CKD. Conclusions and recommendations: Time dependent SBP and DBP were strongly associated with increased risk of CKD. Incidence of CKD was relatively high compared with previous similar studies. Age, HDL-C level, presence Diabetes mellitus, and proteinuria were found to be significant predictors for time to CKD. Health professionals should give greater attention to the identified risk factors for CKD were recommended.