Joint Modeling of Blood Pressure Measurements and Survival Time to Cardiovascular Disease Complication among Hypertension Patients Follow-up at DebreTabor Hospital, Ethiopia

Abstract

Introduction

Hypertension is also referred to as a silent killer and a leading factor for cardiovascular disease complication in the world today. This study aimed to identify the factors that affect longitudinal outcomes and survival time for cardiovascular disease complications among patients with hypertension.

Methods

A retrospective cohort study was conducted among a randomly selected sample of 178 outpatients with hypertension at the Debre Tabor Specialized Hospital between September 2017 and December 2019. Three different models were used to analyze the data: the bivariate mixed-effects model, Cox proportional hazard model, and bivariate joint model for longitudinal and survival sub-models linked by shared random effects.

Results

Bivariate mixed-effects and Cox proportional hazards survival sub-models were jointly preferred based on the minimum Akaike Information Criterion value. The estimated values of the association parameters were 0.0655 (p = 0.0270) and 0.963 (p = 0.0387), indicating that the association between systolic and diastolic blood pressure with time to event was guaranteed. The joint bivariate mixed-effects model analysis showed that patients with hypertension with a family history of hypertension and clinical stage II hypertension have a high chance of developing cardiovascular disease complications and have high average systolic and diastolic blood pressure compared to their counterparts. Patients with hypertension and diabetes have higher systolic and diastolic blood pressure than their counterparts.

Conclusion

Generally, systolic and diastolic blood pressure stabilized over the follow-up period of treatment, while sex and residence were statistically insignificant to the survival time of cardiovascular disease complication. Health professionals and concerned bodies should therefore focus on patients with comorbidities, older age, and poor adherence to hypertension control and cardiovascular disease complications using technology, such as text messaging, and mobile application to promote cardiovascular health at early stage. It is important to provide early interventions for these groups of people, especially for those with family history.

Keywords:

• joint model
• multiple longitudinal assessments
• time to event outcome

Abbreviations

AIC, Akaike information criteria; BDU, Bahir Dar University; BIC, Bayesian information criteria; CI, confidence Interval, DTHS: DebreTabor specialized hospital; FHCVD: Family history of cardiovascular disease; FHHTN: Family history of hypertension; HR: Hazard ratio; HTN, Hypertension; KM, Kaplan Meier; NCD, Non-communicable disease; SBP: Systolic blood pressure; SHTN: Stage of hypertension; WHO, World Health Organization.

Data Sharing Statement

The datasets used and/or analyzed during the current study are available from the first author upon reasonable request.

Ethical Approval and Consent to Participate

The data used in the current investigation were collected by the health staff for outpatient treatment. To use the previously collected data, ethical clearance was obtained from the Ethical Review Board of Bahir Dar University (ref. no. RCS/0102/12). Informed consent was waived due to the anonymized data. This study was conducted in accordance with the Declaration of Helsinki, which states that in medical research using identifiable human material or data, physicians must normally seek consent for the collection, analysis, storage, and/or reuse.

Acknowledgments

The authors are indebted to the Science College Research, Community Service, and Postgraduate Office of Bahir Dar University for financial support and to the Debre Tabor Hospital staff who provided support during data collection.

Author Contributions

All authors made a significant contribution to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis and interpretation, or in all these areas; took part in drafting, revising or critically reviewing the article; gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.

Disclosure

This paper is based on the thesis of Abebe Nege Zelelew. It has been published on (https://ir.bdu.edu.et/handle/123456789/11200). The authors declare that they have no conflicts of interest in this work.

Additional information

Funding

Data collection funding was provided by the College of Science Research, Community Service, and the Postgraduate Office of Bahir Dar University.