Rural-urban difference in the prevalence of hypertension in West Africa: a systematic review and meta-analysis

Abstract

Urbanisation is considered a major contributor to the rising prevalence of hypertension in West Africa, yet the evidence regarding rural-urban differences in the prevalence of hypertension in the region has been mixed. A systematic literature search of four electronic databases: PubMed, Embase, African Journals Online, and WHO's African Index Medicus; and reference lists of eligible studies was carried out. Original quantitative studies describing the rural-urban difference in the prevalence of hypertension in one or more countries in West Africa, and published in English language from the year 2000 to 2021 were included. A random effects meta-analysis model was used to estimate the odds ratio of hypertension in rural compared to urban locations. A limited sex-based random effects meta-analysis was conducted with 16 studies that provided sex-disaggregated data. Of the 377 studies screened, 22 met the inclusion criteria (n = 62,907). The prevalence of hypertension was high in both rural, and urban areas, ranging from 9.7% to 60% in the rural areas with a pooled prevalence of 27.4%; and 15.5% to 59.2% in the urban areas with a pooled prevalence of 33.9%. The odd of hypertension were lower in rural compared to urban dwellers [OR 0.74, 95% CI: 0.66-0.83; p < 0.001]. The pooled prevalence of hypertension was 32.6% in males, and 30.0% in females, with no significant difference in the odds of hypertension between the sexes [OR 0.91, 95% CI: 0.8-1.05, p = 0.196]. Comprehensive hypertension control policies are needed for both rural, and urban areas in West Africa, and for both sexes.

Fig. 1. Map of Africa showing West Africa with ECOWAS member states in highlights.

Insert showing the number of included studies from individual countries.

Fig. 2. PRISMA Flow diagram of study selection.

Number of records excluded at each stage with reasons provided. HTN hypertension, AJOL African Journals Online, WHO AIM World Health Organisation’s African Index Medicus.

Fig. 3. Rural-urban difference in the prevalence of hypertension in West Africa.

Results from the random effects meta-analysis model indicate a lower odd of hypertension among persons living in rural compared to urban areas.

Fig. 4. Rural-urban difference in the prevalence of hypertension in West Africa after excluding persons living in semi-urban areas.

Significantly lower odds of hypertension in persons living in rural compared to urban areas still present after excluding persons living in semi-urban areas.

Fig. 5. Contour-enhanced funnel plot for evaluating bias and heterogeneity among the included studies.

Plot was statistically symmetrical over the pooled odds ratio estimate.

Fig. 6. Sex-based analysis of prevalence of hypertension in West Africa with males as the referent.

No significant difference in the odds of hypertension between males and females found.