Rate and Risk of All Cause Mortality among People with Known Hypertension in a Rural Community of Southern Kerala, India: The Results from the Prolife Cohort

Abstract

Background: Hypertension is one of the most important determinants of death due to vascular damage and is fast emerging as a high burden disease in India. However, its documentation is poor in the country. This study aims to estimate the rate and the causal pattern of mortality in a cohort of people with high blood pressure as compared to normotensives.

Methods: The study setting is Varkkala, a rural village in southern Kerala, India, and the study design was that of a prospective cohort. A total of 77,881 participants of age 20 years and above were considered for analysis. The rate and risk of all cause mortality (death due to any cause) among hypertensives were quantified and compared against the normotensives. The causes of death were also analyzedin both the groups. Cox proportional hazard models were created to estimate the hazard ratios of death among hypertensives adjusted for sociodemographic factors, behaviors, and comorbidities.

Results: The incidence proportion of deaths in the study was 4.28% during the follow‑up period of 6 years. The relative risk of mortality was 3.13 (CI: 2.91-3.37) in the high BP group. The age‑adjusted hazard ratio of all cause mortality for the high BP group was 2.96 (2.56-3.42). Coronary artery disease was the major cause of death among the subjects with high BP.

Conclusions: The study revealed high prevalence of hypertension in the study population. A person with hypertension is at three times higher risk of death due to any cause compared to a normotensive individual even after adjustment for age.

Keywords: All cause mortality, hypertension, hypertension and death, hypertension in Kerala