Risk stratification of hypertension in South Africa: a systematic review with meta-analysis

Hypertension is a leading cause of morbidity and mortality in South Africa. Evidence on risk factors is scattered across study designs, limiting clinical decision support. This review synthesizes evidence to classify hypertension risk factors to strengthen prediction models and prevention strategies through causal integration.

A systematic review followed PRISMA 2020, searching PubMed, Scopus, Web of Science, Medline, CINAHL, and SABINET. Two independent reviewers screened and extracted data. Narrative synthesis and meta-analysis were performed, and risk factors were classified within a framework. Causal pathways were mapped using directed acyclic diagram.

Eleven studies with 49,058 participants from nine provinces were included. Strongest risk factors were advanced age (OR: 3.67, CI 1.7-7.6) and diabetes (OR: 1.85, CI 1.39-2.46), followed by low education (OR: 1.75, CI 1.56-2.00), ethnicity (OR: 1.57, CI 1.23-2.01), and socioeconomic status (OR: 1.14, CI 1.01-1.30). Critical risk thresholds (Rw: 3.8 and 5.5) correspond to the 75th and 50th percentiles. A prediction model (Age-Ethnicity-Diabetes) achieved Rw 6.0 and net GTT 2.49. Higher education, improved socio-economic status, and diabetes management were primary prevention strategies (Rw: 4.71, net GTT: 2.49). Age and diabetes emerged as "necessary causes".

Older adults (≥50 years), individuals with diabetes, mixed-race ethnicity, and lower socioeconomic status are priority groups. Screening should be prompted by age and diabetes.

https://www.crd.york.ac.uk/PROSPERO/view/CRD420251026501, PROSPERO ID: CRD420251026501.