A Systematic Review and Meta-Analysis of the Effects of Outdoor Education Programs on Adolescents' Self-Efficacy.

While prior research has generally found Outdoor Education Programs (OEPs) to be beneficial to adolescents' self-efficacy, we sought to conduct a meta-analytic review of prior studies in this area in order to pinpoint the key elements to OEPs' effectiveness. Following Cooper's guidelines for synthesis research and meta-analysis, we searched six electronic databases for relevant articles: PubMed, Sciencedirect, Medline, PsycArticles, and Behavioral Sciences Collection of EBSCO, and Eric. Selection criteria were: Populations, Interventions, Comparators, Outcomes, Study Design (PICOS), and Methodological Index for Non-randomized Studies (MINORS). We estimated the effect size of the selected studies with a 95% confidence interval (CI), estimated I-squared (I2) for heterogeneity analysis and analyzed publication bias by Egger's test. After excluding many studies, we reviewed 12 studies with 2,642 participants that were deemed to be eligible for final analysis. We discovered a high level of heterogeneity (I-squared value =82.474) in the findings of the selected studies. Our meta-analyses revealed that adolescents participating in OEPs enhanced their self-efficacy (medium effect size; Hedges's g = 0.597) but this enhancement was moderated by participants' mental health status, the length of the experiments, study groups, and the duration of the intervention. We found no evidence of publication bias (Egger: bias = 2.001, 95% CI = -0.736 to 4.739, p = .137). We discussed our research limitations and the theoretical and practical implications of these findings and made recommendations for future research.