Social epidemiology of hypertension in Buffalo City Metropolitan Municipality (BCMM): cross-sectional study of determinants of prevalence, awareness, treatment and control among South African adults

OBJECTIVES: This study examined hypertension prevalence, awareness, treatment and control and their determinants among adults attending health facilities in Buffalo City Metropolitan Municipality (BCMM) in the Eastern Cape. DESIGN: A cross-sectional analytical study. SETTINGS: The three largest outpatient clinics in BCMM. PARTICIPANTS: Ambulatory adults (aged 18 years and over) attending the study settings during the study period (n=998). PRIMARY OUTCOME MEASURE: The prevalence of hypertension (systolic blood pressure (BP) of ≥140 mm Hg and/or a diastolic BP of ≥90 mm Hg or current medication for hypertension), the awareness of it (prior diagnosis of it) and its treatment and control (Eighth Joint National Committee Criteria of BP <140/90/90 mm Hg). SECONDARY OUTCOME MEASURE: Associated factors of hypertension, hypertension unawareness and uncontrolled hypertension. RESULTS: Of the 998 participants included, the prevalence of hypertension was 49.2%. Hypertension unawareness was reported by 152 participants (23.1%) with significant gender difference (p=0.005). Male sex, age <45 years, higher level of education, single status, current employment, higher monthly income, current smoking, alcohol usage, absence of diabetes and non-obese were significantly associated (p<0.05) with hypertension unawareness. Of the participants who were aware of having hypertension (n=339), nearly all (91.7%, n=311) were on antihypertensive medication and only 121 participants (38.9%) achieved the BP treatment target. In the multivariate logistic regression model analysis, ageing (95% CI 1.9 to 4.4), being married (95% CI 1.0 to 2.0), male sex (95% CI 1.2 to 2.3), concomitant diabetes (95% CI 1.9 to 3.9), lower monthly income (95% CI 1.2 to 2.2), being unemployed (95% CI 1.0 to 1.9) and central obesity (95% CI 1.5 to 2.8) were the significant and independent determinants of prevalent hypertension. CONCLUSION: The prevalence and awareness of hypertension was high in the study population. In addition, the suboptimal control of BP among treated individuals, as well as the significant cardiovascular risk factors, warrant the attention of health authorities of BCMM and the country.