What Are the Effective Interventions for Preventing Substance Use Among Adolescents and Young People in Sub Saharan Africa? a Systematic Review

Background: Adolescents and young people who engage in substance use are at more risk of academic difficulties, mental health problems and health-related problems. Studies indicated that the prevalence of substance use among this population in sub-Saharan Africa (SSA) is 41.6%. Despite the need for understanding effective preventive interventions to address this problem, there has only been one systematic review of these interventions in this region, yet it was not focused on this age group. Thus, to better understand these interventions, this systematic review addressed the following research objectives: 1) identify and describe the types of interventions and common outcomes in this population, 2) describe the methodological rigor of the intervention studies, and 3) determine what types of interventions were most effective (school-based vs non-school based) based on the study’s methodological rigor and outcomes.

Methods: A systematic search of 6 databases was conducted through the EBSCO search engine following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Inclusion criteria included: 1) quantitative interventions evaluating substance use-related outcomes (2) published between 2000-2024 in SSA (3) pre-posttest, quasi-experimental, or experimental designs, (4) published in English peer-reviewed journals. To evaluate the methodological rigor of each study, the 12-item Methodological Quality Rating Scale was used with possible total scale scores ranging from 0-14. Studies that scored at or above the mean were considered high rigor, and those below the mean were low rigor. Strength of study evidence combined outcome significance with study rigor where:(1) strong evidence (high rigor and significant outcomes); (2) promising (low rigor and significant outcomes); (3) weak evidence (high and low rigor and non-significant outcomes).

Results: Eleven studies met the inclusion criteria for this review. Intervention types were categorized by the site of the interventions. The majority of the interventions were conducted in schools (n=8) versus non-schools (n=3) which included social media-based, clinic, and inner cities. The MQRS scores ranged from 6-12, with 7 studies with total scores above the mean of 9.8. Methodological strengths were reporting attrition, dosage and treatment integrity. Methodological weaknesses were a lack of blinding and a few multiple sites. Among studies that measured knowledge, both school and non-school-based studies were significant, yet more non-school-based were of higher rigor (i.e., stronger evidence). All 5 studies that measured attitudes were school-based: 4 were strong and 1 was promising (significant but low rigor). Ten studies measured substance use-related behavior. Out of these 10 studies, 5 were strong, 2 were promising 3 were weak. Among the non-school-based interventions measuring substance use-related behaviors (3 studies): 2 were strong and 1 was promising while among the school-based interventions (7 studies): 3 were strong, 3 were weak, and 1 was promising.

Conclusions and Implications: Both school-based and non-school-based interventions were equally effective in improving knowledge and attitudes. Evidence is mixed about whether school-based or non-school-based are more effective for substance-use behaviors. Future research is needed to identify other intervention characteristics that may be contributing to the variations in the effectiveness of addressing behaviors.