Socioeconomic and modifiable predictors of blood pressure control for hypertension in primary care attenders in the Western Cape, South Africa

BACKGROUND. Low socioeconomic status is associated with the risk of hypertension. There are few reports of the effect of socioeconomic and potentially modifiable factors on the control of hypertension in South Africa (SA). OBJECTIVES. To investigate associations between patients' socioeconomic status and characteristics of primary healthcare facilities, and control and treatment of blood pressure in hypertensive patients. METHODS. We enrolled hypertensive patients attending 38 public sector primary care clinics in the Western Cape, SA, in 2011, and followed them up 14 months later as part of a randomised controlled trial. Blood pressure was measured and prescriptions for antihypertension medications were recorded at baseline and follow-up. Logistic regression models assessed associations between patients' socioeconomic status, characteristics of primary healthcare facilities, and control and treatment of blood pressure. RESULTS. Blood pressure was uncontrolled in 60% (1 917/3 220) of patients at baseline, which was less likely in patients with a higher level of education (p=0.001) and in English compared with Afrikaans respondents (p=0.033). Treatment was intensified in 48% (892/1 872) of patients with uncontrolled blood pressure at baseline, which was more likely in patients with higher blood pressure at baseline (p<0.001), concurrent diabetes (p=0.013), more education (p=0.020), and those who attended clinics offering off-site drug supply (p=0.009), with a doctor every day (p=0.004), or with more nurses (p<0.001). CONCLUSION. Patient and clinic factors influence blood pressure control and treatment in primary care clinics in SA. Potential modifiable factors include ensuring effective communication of health messages, providing convenient access to medications, and addressing staff shortages in primary care clinics.