Comparative Effectiveness of Dentist-Led Lecture Versus Self-Directed Learning on Tobacco Knowledge and Susceptibility Among Nigerian Adolescents: A School-Based Cluster-Randomized Controlled Trial

Abstract

Background: Adolescents’ tobacco susceptibility is a strong predictor of future initiation; yet rigorously evaluated school-based interventions in low- and middle-income countries (LMICs) remain scarce. This study compared the effectiveness of dentist-led lectures versus self-directed learning in improving tobacco-related knowledge and reducing tobacco susceptibility among Nigerian adolescents. Methodology: Parallel, 2-arm, cluster-randomized controlled trial involving 720 students (13-19 years) across 8 secondary schools in Ibadan, Nigeria, stratified by school type (public vs private). Schools were randomized to the Dentist-Led Lecture Group (DLG) or Self-Directed Learning Group (SLG). The DLG received a single 45-minute tobacco education lecture; the SLG received customized anti-tobacco notebooks and posters. Outcomes were tobacco-related knowledge scores and susceptibility to tobacco use, assessed at baseline, immediate post-intervention, and 6-month follow-up. Analyses included t -tests, repeated-measures ANOVA, McNemar tests, and logistic generalized estimating equation (GEE) with exchangeable correlation structure and robust standard errors (α = .05). Results: Mean (standard deviation) knowledge scores improved from baseline to 6 months in both groups (DLG: 5.2 [3.1]-9.7 [2.3]; SLG: 4.7 [3.5]-8.8 [2.7]; both P < .001), with no between-group difference ( P = .200). Baseline susceptibility was comparable (DLG 16.4%; SLG 20.3%; P = .178). At 6 months, susceptibility declined in DLG to 7.3% ( P < .001) and SLG to 15.0% ( P = .251). Prespecified subgroup analyses showed susceptibility decreased in private schools for both groups (DLG 18.9%-6.6%, P = .002; SLG 17.0%-8.0%, P = .012), but not in public schools (DLG 14.1%-8.0%, P = .152; SLG 23.6%-24.1%, P = .688). In GEE models averaged across time points, SLG participants had higher population-averaged odds of susceptibility than DLG (aOR = 1.98, 95% confidence interval: 1.45-2.70). Conclusions: Both interventions improved tobacco-related knowledge at similar rates, but dentist-led education was associated with lower odds of tobacco susceptibility. This trial demonstrates the value of scalable school-based approaches for adolescent tobacco prevention in LMICs.