A multicomponent secondary school health promotion intervention and adolescent health: An extension of the SEHER cluster randomised controlled trial in Bihar, India

Strengthening Evidence base on scHool-based intErventions for pRomoting adolescent health (SEHER) is a multicomponent, whole-school health promotion intervention delivered by a lay counsellor or a teacher in government-run secondary schools in Bihar, India. The objective of this study is to examine the effects of the intervention after two years of follow-up and to evaluate the consistency of the findings observed over time. We conducted a cluster randomised trial in which 75 schools were randomised (1:1:1) to receive the SEHER intervention delivered by a lay counsellor (SEHER Mitra [SM]) or a teacher (Teacher as SEHER Mitra [TSM]), respectively, alongside a standardised, classroom-based life skills Adolescence Education Program (AEP), compared to AEP alone (control group). The trial design was a repeat cross-sectional study. Students enrolled in grade 9 (aged 13-15 years) in the 2015-2016 academic year were exposed to the intervention for two years and the outcome assessment was conducted at three time points─at baseline in June 2015; 8-months follow-up in March 2016, when the students were still in grade 9; and endpoint at 17-months follow-up in December 2016 (when the students were in grade 10), the results of which are presented in this paper. The primary outcome, school climate, was measured with the Beyond Blue School Climate Questionnaire (BBSCQ). Intervention effects were estimated using mixed-effects linear or logistic regression, including a random effect to adjust for within-school clustering, minimisation variables, baseline cluster-level score of the outcome, and sociodemographic characteristics. In total, 15,232 students participated in the 17-month survey. Compared with the control group, the participants in the SM intervention group reported improvements in school climate (adjusted mean difference [aMD] = 7.33; 95% CI: 6.60-8.06; p < 0.001) and most secondary outcomes (depression: aMD = -4.64; 95% CI: -5.83-3.45; p < 0.001; attitude towards gender equity: aMD = 1.02; 95% CI: 0.65-1.40; p < 0.001; frequency of bullying: aMD = -2.77; 95% CI: -3.40 to -2.14; p < 0.001; violence victimisation: odds ratio [OR] = 0.08; 95% CI: 0.04-0.14; p < 0.001; and violence perpetration: OR = 0.16; 95% CI: 0.09-0.29; p < 0.001). There was no evidence of an intervention effect in the TSM group compared with control group. The effects of the lay counsellor-delivered intervention were larger for most outcomes at 17-months follow-up compared with those at 8 month