A systematic review and meta-analysis of factors associated with adolescent substance use in Africa, 2000 to 2020.

Abstract

Background and aims: Adolescent substance use is a growing public health concern in Africa, yet little is known about the contextual factors of substance use among young African populations. This systematic review identified factors associated with substance use among adolescents (aged 10-19 years) in Africa.

Methods: This review was conducted in line with PRISMA guidelines. We searched six databases (from January 2000 to December 2020): PubMed, Cochrane Library, African Journals Online (AJOL), Google Scholar, ScienceDirect and World Health Organization (WHO) African Index Medicus. We included population-based observational studies reporting on factors associated with adolescent substance use across Africa. Study screening was conducted by at least four independent reviewers who resolved discrepancies through discussion and consensus. All included studies were analysed in a narrative synthesis. Studies providing sufficient statistics, i.e. three or more reporting the same outcome and exposure/predictor, were included in meta-analyses.

Results: Sixty-three peer reviewed studies that were full text accessible were included. The majority were cross-sectional surveys. Factors associated with adolescent substance use identified were linked to individual, family, socioenvironmental and non-familial social networks determinants. Results from both the narrative synthesis and meta-analysis revealed that being male and an older adolescent were significantly associated with adolescent substance use. Combined odds ratio (OR) of males who currently smoke compared with females was 1.81 [95% confidence interval (CI) = 1.37-2.39; 6 studies, 13 443 participants, I² = 59.67%]. Additional meta-analysis outcomes found that having a friend who smokes was associated with tobacco smoking. Combined OR of 'ever-smokers' with a friend who smoked was 4.83 (CI = 2.56-9.10; 3 studies, 18 858 participants, I² = 79.21%). Having a family member who smokes was associated with smoking initiation (OR = 2.99; CI = 2.67-3.35; 3 studies, 18 858 participants, I² = 0%) and current smoking (OR = 2.33; CI = 2.23-2.45; 4 studies, 13 282 participants, I² = 0%).

Conclusion: Multiple factors that operate on individual, family and societal levels influence adolescent substance use in Africa. Key factors of adolescent substance use in Africa appear to include being male, being an older adolescent and being exposed to peer substance use.