Supplementary Material for: Colonic diverticulosis at colonoscopy in Africa: a systematic review and meta-analysis of pooled estimates

Background: There is need to ascertain any epidemiologic shift of diverticulosis among Africans with traditionally high fiber diet consumption patterns and rare diverticulosis prevalence.
Methods: We systematically searched PubMed, Scopus, Cochrane Library, African Journal Online (AJOL) and Google Scholar. Eligibility criteria included full text observational and experimental human colonoscopy studies on asymptomatic and symptomatic African population from 1985-2022. Case reports, conference abstracts, dissertations, systematic reviews, and studies lacking colonoscopy findings were excluded. NIH quality assessment tool for observational cohort and cross-sectional studies was used to assess risk of bias. Meta-analysis was performed using the random-effect model. Heterogeneity was assessed using inconsistency (I2) statistics.
Results: Thirty studies were included. Pooled prevalence rate of colonic diverticulosis was 9.1% (95%CI 7.1-11.2; I2=96.3%) with highest regional prevalence rate in West African studies at 11.3% (95%CI 7.6-14.9; I2=96.2%). Proportion of individuals with diverticulosis ≥50 years and male sex were 86.9 % (95%CI 80.5-92.1) and 65.2% (95%CI 55.0-74.8), respectively. Left colon had the highest diverticulosis frequency [37% (148/400)].
Bleeding/inflammation complications were sparingly detected [OR 0.2 (95%CI 0.03-0.75;p<0.0001)].
Conclusion: Colonic diverticulosis was most common in males aged >50. Left was colon predominantly affected. Regional variation in detection of diverticulosis was reported across Africa.