Incident hypertension in Urban Slums of Central India: A prospective cohort study

Abstract

Background: National Program for prevention and control of cancer, diabetes, cardiovascular diseases and stroke (NPCDCS) in India envisages annual screening of adults over age of 30 years for hypertension. It is followed by confirmation and further linkage for treatment and health promotion interventions. We aimed to estimate incidence rate of hypertension and to identify risk factors for same, so that it is useful for program implementation. Methods: We established a cohort of adults residing in urban slums of Bhopal, who were registered in a baseline cardio-vascular risk assessment survey, which was performed between November-2017 and March-2018. Blood pressure assessment was done at-least thrice at baseline for diagnosis of hypertension, which was defined as SBP >/= 140 mm Hg or DBP >/= 90 mm Hg on two or more occasions. Participants who did not have a diagnosis of hypertension, were followed up during April-June 2019. Results: Of the 5673 participants assessed at baseline, 4185 did not have hypertension of which 3199 (76.4%) were followed up after a median on 1.25 years (IQR 1.08-1.60) and a total of 170(5.31%) individuals were detected with incident hypertension. Overall incidence rate of HTN was 4.1 (95%CI 3.54-4.75) per 100 person-years of follow-up. On multi-variate analysis, age (RR 1.79; 95%CI 1.1-2.92 for age > 60 years) and being illiterate (RR 1.9; (95%CI 1.35-2.69) were significant predictors of incident hypertension. Individuals who had pre-hypertension at baseline also had a significantly increased risk of developing hypertension (RR 3.02; 95%CI 2.06-4.44). Conclusions: We found that incidence of hypertension in urban slums of central India is higher with increasing age and in men. Illiteracy and prehypertension are other determinants. We also demonstrate feasibility of establishing a cohort within the public-health delivery system, driven by efforts of Community Health Workers. Key words: Hypertension, prehypertension, Community Health Worker, Urban slums.