Method: This paper is the second of a Four-Part Series paper of a previous systematic mapping review of peer-reviewed literature on ageing studies conducted in SSA. We updated the literature search to include additional 32 articles, a total of 544 articles included in this paper. Downs & Black checklist, Case Report guidelines checklist, the 45-items Lundgren et al. checklist, and the Mixed Method Appraisal Tool were used to assess the methodological quality of quantitative, case reports, qualitative, and mixed-method studies. Quality assessment was piloted and conducted in pairs for each study type. Depending on the checklist, each study was classified as excellent, good, fair, or poor.
Result: Of the 544 articles, we performed the quality assessment of a total of 451 quantitative studies [Randomized control trials (RCTs) and pre-post (n=15), longitudinal (n=122), case-control (n=15) and cross-sectional (n=300); 4 case reports, 74 qualitative and 15 mixed-method studies. Only 20.4% (n=111) articles were of high quality [one RCT, 27 longitudinal, 4 case-control, 48 cross-sectional studies, 19 qualitative, and 12 mixed-method studies]. The remaining 433 were rated as moderate quality (n=292, 53.7%), fair quality (n = 96, 17.7%) and poor quality (n = 45, 8.2%). Most (80%) quantitative articles’ sample size is small, resulting in insufficient power to detect a clinically or significant important effect. Three-quarter (75%) of the qualitative studies did not report their research team characteristics and a reflexivity component of the 45-items Lundgren et al. checklist. Mixed-method studies with low quality did not report the qualitative studies properly.
Conclusion: We conclude that the methodological and quality reporting of published studies on ageing in SSA show variable quality, albeit primarily moderate quality, against high quality. Studies with a large sample size are recommended, and qualitative researchers should provide a section on research team members’ characteristics and reflexivity in their paper or as an appendix.