May Measurement Month 2018: An Analysis of Blood Pressure Screening Results From Botswana

Abstract

Objective: During the May Measurement Month 2018 (MMM18) campaign, we aimed to raise hypertension awareness and measure blood pressure across different communities in Botswana. Design and method: Study sites were four large villages and Gaborone (capital city). Screening sites included shopping malls, train stations, churches and workplaces. Individuals aged over 18 years were recruited through fliers, word of mouth and volunteer walk-ins at the sites. Demographic and risk factor data were collected through a questionnaire prior to measuring three blood pressure (BP) readings per participant. Weight was measured while height was usually estimated. Hypertension was defined as: SBP above 140 mmHg or DBP above 90 mmHg or taking antihypertensive medication. The mean of readings 2 and 3 was used, and was estimated using multiple imputation where missing. Ethical clearance was obtained from the Ministry of Health and University of Botswana. Results: Amongst 4,599 participants whose BPs were measured, 54.5% were female, mean age was 35.9 years. A total of 1,510 (32.8%) participants were hypertensive with 712 (47.1%) aware of the hypertension. In participants not taking antihypertensive medication, the association between age and sex with SBP showed a linear increase, with the mean BP in males prominently higher than the mean BP in females across ages below 85–90 years, where they became equal. The DBP association showed an inverted U curve, with the mean DBP in males exceeding the mean DBP in females at age of 25 years, and the peak on the male curve at ages 45–50 years, while in females it was at ages 50–55 years. Only 35.2% of hypertensives were on anti-hypertensive treatment with 54.4% having controlled BP. Amongst all hypertensives, only 19.1% had controlled BP. Factors associated with higher BP included obesity, more than 1unit of alcohol/week and BP measured on Sunday. Conclusions: Less than half (52.9%) of those identified to have hypertension during MMM18 campaign were aware of their condition, despite the escalating prevalence of hypertension in the country. Regular BP awareness and opportunistic BP measurement campaigns like the MMM are recommended to improve detection and control of hypertension and other cardiovascular risk factors.