Prevalence and associations of hypertension detection, treatment and control in Cape Town.

AIM: Globally, the prevalence of hypertension is high and rising; however, hypertension care remains suboptimal, including in South Africa. Therefore, the aim of this study was to determine the prevalence and associations of hypertension detection, treatment and control in > 21-year-old urban black residents with hypertension in Cape Town, South Africa.

METHODS

In this randomly selected community-based cross-sectional study, data collection comprised administered questionnaires, clinical measurements and fasting biochemical analyses, including oral glucose tolerance tests. Hypertension was defined as blood pressure ≥ 140/90 mmHg or known hypertension on treatment. Separate logistic regression models evaluated the associations with hypertension detection, treatment and control. Each model included sociodemographic characteristics, problem drinking, daily tobacco smoking, family history of hypertension, obesity (body mass index ≥ 30 kg/m2), and comorbidities of diabetes, high low-density lipoprotein cholesterol and chronic kidney disease (CKD).

RESULTS

Among 460 participants with hypertension, 65% were women and the mean age was 50.7 (SD ± 12.1) years. Prevalence of hypertension detection among participants with hypertension (62.4%), treatment among the detected (75.6%) and control among the treated (57.1%) were sub-optimal, with better rates in women (73.6%, 80.0%, 59.1%, respectively) than in men (41.6%, 61.2%, 48.8%) (p < 0.05 for detection and treatment). Hypertension detection among participants with hypertension was associated with age ≥ 45 years, female gender (OR: 3.56, 95%CI: 1.94-6.55), a family history of hypertension (OR: 1.81, 95% CI: 1.09-3.00), ≤ 7 years of education (OR: 1.76, 95%CI: 1.02-3.03), ≥ 50% of life spent in city (OR: 1.82, 95%CI: 1.07-3.10) and comorbid diabetes (OR: 3.51, 95%CI: 1.80-6.86) or CKD (OR: 6.27, 95%CI: 1.31-30.10). The poorest participants were half as likely as their counterparts to have their hypertension detected (OR: 0.51, 95%CI: 0.28-0.92). Treated hypertension in those detected was significantly associated with female gender (OR: 3.29, 95% CI: 1.42-7.67) and just missed being associated with comorbid diabetes (OR: 2.00, 95% CI: 0.99-4.03). Hypertension control among participants who were treated was significantly associated with female gender (OR: 2.36, 95%CI: 1.01-5.51) in the logistic regression analyses.

CONCLUSIONS

Participants who were female and with comorbid diabetes were more likely to have better hypertension care overall, while the poorest and less urbanised participants were less likely to have their hypertension detected. Strategies are required to ensure equitable distribution of hypertension care. In-depth research is required to understand the contributors to suboptimal hypertension care, which likely differ by age, gender, socioeconomic status and level of care.