Prevalence and associated factors of active smoking among individuals living with hypertension and/or diabetes in Africa: a systematic review and meta-analysis protocol

INTRODUCTION: Tobacco use significantly increases cardiovascular complications in people living with hypertension and/or diabetes. We aim to summarise data on the prevalence and factors associated with active smoking in these conditions in Africa. METHOD AND ANALYSIS: We will search PubMed, Embase, Google Scholar and African Journals Online for relevant abstracts of studies on active smoking in individuals living with diabetes and/or hypertension published from 1 January 2000 to 31 December 2016, with no language restriction. Additionally, relevant unpublished papers and conference proceedings will be checked, as well as references of included articles. Two investigators will independently screen, select studies, extract data and assess the risk of bias in each study. Data will be analysed using Stata software (Stata V.14, Texas, USA). The study-specific estimates will be pooled through a random-effects meta-analysis model to obtain an overall summary estimate of the prevalence of smoking across studies. Also, we will assess factors associated to smoking. Heterogeneity of studies will be evaluated by the χ2 test on Cochrane’s Q statistic. Funnel plots analysis and Egger’s test will be done to detect publication bias. Results will be presented by geographic region (central, eastern, northern, southern and western Africa). A p value less than 0.05 will be considered significant for factors associated to smoking. ETHICS AND DISSEMINATION: This study is based on published data, and therefore ethical approval is not a requirement. This systematic review and meta-analysis is expected to serve as a basis for designing cost-effective interventions to reduce and prevent smoking in patients with diabetes and/or hypertension, and as a guide for future research based on the remaining gaps. The final report of this study in the form of a scientific paper will be published in peer-reviewed journals. Findings will further be presented at conferences and submitted to relevant health authorities.