Epidemiology of Road Traffic Accidents and Injuries in Nigeria: A Protocol for Systematic Review and Meta-analysis

Background: About 1.35 million people die annually worldwide due to road traffic accidents. Road traffic injuries cause considerable economic losses to individuals, their families, and to nations as a whole. About 93% of the world's fatalities on the roads occur in low-and middle-income countries, even though these countries have approximately 60% of the world's vehicles. Road Traffic Accidents constitute the third leading cause of trauma related deaths in Nigeria. It is a substantial public health problem that deserves a systematic review.Methods and Analysis: We developed a search strategy using MeSH, text words and entry terms. Nine databases will be searched, including PubMed, African Journal Online, Embase, Google Scholar, Scopus, Cochrane Library, CINAHL, Web of Science and ResearchGate. Only observational studies, retrievable in the English language will be included. The primary outcome is prevalence of road traffic injuries in Nigeria. The secondary outcomes include proportion of road traffic accidents in Nigeria, patterns, predictors and consequences of road traffic accidents in Nigeria. Identified studies will be screened and selected based on inclusion criteria using Rayyan QCRI screening tool, by independent reviewers with dual blinding. Data items will be extracted into predefined forms in Microsoft Excel before exporting to CMA version 3 for analysis. Every selected study will have their NIH quality scores and Cochrane risk of bias reported. Studies will be assessed for methodological and statistical heterogeneity. Publication bias will be assessed using Funnel Plots and test of asymmetry. Results will include forest plots, pooled prevalence with standard error, variance, relative weights assigned to studies and heterogeneity test. Further analysis will include subgroup analysis and meta-regression using both categorical and quantitative variables.Discussion: This protocol will enable a transparent, accurate and reliable method for determining pooled prevalence, standard error and 95% CI of road traffic injuries in Nigeria. Patterns and outcomes of RTA in Nigeria will also be assessed. Evidence generated by this protocol will likely inform policy on prevention of RTA in NigeriaTrial Registration Number: This protocol is registered with PROSPERO, with registration number CRD42021226956.