Joint Modeling of Longitudinal Blood Pressure and Time to Complications Among Hypertensive Patients: A Retrospective Cohort Study in Mekelle, Ethiopia, 2018-2024

Abstract

Introduction: Hypertension is one of the 21st century emerging major public health problem, which is a strong risk factor for myocardial infraction, heart failure, ischemic or hemorrhagic stroke, chronic kidney disease, and eye disorder. Despite its significance, limited studies have investigated the association between longitudinal blood pressure measurements and the time to development of complications among hypertensive patients. Objectives: To determine the predictors, association between longitudinal blood pressure measurements and time to develop complications among hypertensive patients in ACSH and Mekelle General Hospital, Tigray, Ethiopia, 2018-2024. Methodology: A retrospective cohort study among 403 adult hypertensive patients with no complications from the beginning of follow up in Ayder Comprehensive Specialized Referral Hospital and Mekelle General Hospital from January 2018 to March 2024 was included. Data from patient’s medical record was collected using Kobo toolbox and exported to Stata version 17 and R 4.4.3 for data management and analysis. A bivariate mixed-effects model, Cox proportional hazards model, and a multivariate joint model linking longitudinal and survival sub-models through shared random effects were fitted. The final interpretation was done by hazard ratio. Result: A multivariate joint modeling analysis was the best fitted model based on the minimum Akaike Information Criterion value with an estimated value of the association parameters of 10.4 (p < 0.001) and 4.9 (p = 0.040), supporting the association between systolic and diastolic blood pressure with time to event was statistically significant. The multivariate joint modeling analysis showed that patients with family history of cardiovascular diseases (Hazard Ratio = 4.31), patient with Diabetes mellitus comorbidity (Hazard Ratio = 3.86), patient who take multiple treatment regimens have higher chance of developing hypertension related complications. Both Systolic and Diastolic blood pressure measurements were found to be critical predictors of hypertension complications. Conclusion and Recommendation - This study highlights the importance of effective blood pressure management and the need for targeted interventions that account for family history, clinical comorbidities, and treatment regimens to reduce the risk of complications in hypertensive patients.