Prevalence, awareness, treatment and control of hypertension and their determinants: results from a national survey in Kenya

Background: Hypertension is the most important risk factor for cardiovascular diseases and the leading cause of death worldwide. Despite growing evidence that the prevalence of hypertension is rising in sub-Saharan Africa, national data on hypertension that can guide programming are missing for many countries. In this study, we estimated the prevalence of hypertension, awareness, treatment, and control. We further examined the factors associated with hypertension and awareness.

Method: We used data from the 2015 Kenya STEPs survey, a national cross-sectional household survey targeting randomly selected people aged 18-69 years. Demographic and behavioral characteristics as well as physical measurements were collected using the World Health Organization's STEPs Survey methodology. Descriptive statistics were used to estimate the prevalence, awareness, treatment and control of hypertension. Multiple logistic regression models were used to identify the determinants of hypertension and awareness.

Results: The study surveyed 4485 participants. The overall age-standardized prevalence for hypertension was 24.5% (95% confidence interval (CI) 22.6% to 26.6%). Among individuals with hypertension, only 15.6% (95% CI 12.4% to 18.9%) were aware of their elevated blood pressure. Among those aware only 26.9%; (95% CI 17.1% to 36.4%) were on treatment and 51.7%; (95% CI 33.5% to 69.9%) among those on treatment had achieved blood pressure control. Factors associated with hypertension were older age (p < 0.001), higher body mass index (BMI) (p < 0.001) and harmful use of alcohol (p < 0.001). Similarly, factors associated with awareness were older age (p = 0.013) and being male (p < 0.001).

Conclusion: This study provides the first nationally-representative estimates for hypertension in Kenya. Prevalence among adults is high, with unacceptably low levels of awareness, treatment and control. The results also reveal that men are less aware of their hypertension status hence special attention should focus on this group.