Uncontrolled hypertension among patients with comorbidities in sub-Saharan Africa: protocol for a systematic review and meta-analysis

BACKGROUND: Uncontrolled hypertension is the most important risk factor and leading cause of cardiovascular diseases. It is predicted that the number of people with hypertension will increase, and a large proportion of this increase will occur in developing countries. The highest prevalence of uncontrolled hypertension is reported in sub-Saharan Africa, and treatment for hypertension is unacceptably low. Hypertension commonly co-exists with comorbidities and this is associated with poorer health outcomes for patients. This review aims to estimate the prevalence of uncontrolled hypertension among patients with comorbidities in sub-Saharan Africa. METHODS AND ANALYSIS: All published and unpublished studies on the prevalence of uncontrolled hypertension among patients with comorbidities in sub-Saharan Africa will be included. MEDLINE via OVID, Embase, and Web of Science will be searched to identify all relevant articles published from January 2000 to June 2019. Experts in the field will be contacted for unpublished literature, and Open SIGLE will be reviewed for relevant information. No language restriction will be imposed. Two reviewers will select, screen, extract data, and assess the risk of bias while a third reviewer will arbitrate the disagreements. A meta-analysis will be performed on variables that are similar across the included studies. Proportions will be stabilized before estimates are pooled using a random effects model. The presence of publication bias will be assessed using Egger's test and visual inspection of the funnel plots. This systematic and meta-analysis review protocol will be reported in accordance with the PRISMA-P protocol guidelines. Results will be stratified by country, comorbidity, and geographic region. DISCUSSION: This systematic review and meta-analysis is expected to quantify the magnitude of uncontrolled hypertension among patients with certain comorbid conditions in sub-Saharan Africa to guide policies and interventions. This review is registered in PROSPERO International Prospective Register of Systematic reviews CRD42019108218.