Abstract:
Abstract
Introduction: Hypertension is a chronic disease that has major health problem over the centuries. It is also called high blood pressure, described by three measured quantities, systolic blood pressure, diastolic blood pressure and pulse rate and also it is the major risk factor for cardiovascular disease.
Objective: The objective of the study was to identify factors that affect multivariate longitudinal measures of hypertension and time to develop cardiovascular disease complication among hypertensive outpatients under follow up at DebreTabor General Hospital, Ethiopia.
Methodology: Retrospective study design was conducted from 178 randomly selected hypertensive outpatients at DebreTabor General Hospital under follow-up period from September 2017 to December 2019. The study was used three different models namely; linear mixed effects model for the longitudinal data, cox-proportional hazard model for the time-to-event data and joint model for longitudinal sub models and survival sub model linked by shared random effects.
Result: As compare the overall performance of separate and joint models, joint modeling of multivariate longitudinal measures with the time to event outcome was the best model compared to separate multivariate linear mixed model, then it was evidence that more efficient estimates were made from multivariate joint model. The estimated values of the association parameters were 0.0655(p-value=0.005), 0.0863(p-value=0.0328) and 0.0977(p-value= 0.0084) indicates that association of systolic blood pressure, diastolic blood pressure, and pulse rate respectively with time to event. Hence the relationship between blood pressure as measured by SBP, DBP and PR with time to event was positively significant. Thus, cardiovascular disease complication were higher likely to occur in patients with higher SBP, DBP and PR.
Conclusion: From the findings we conclude that the predictor diabetes, family history of hypertension, stage of hypertension were statistically significant predictors of the SBP, DBP, &PR with time to develop cardiovascular disease complication jointly. The results suggest strongly that to minimize the risk of cardiac complication, it is essential to treat blood pressure efficiently.
Key words: joint model, multiple longitudinal outcoutcomes, time to event outcome