School-based relationship and sexuality education intervention engaging adolescent boys for the reductions of teenage pregnancy: the JACK cluster RCT

Background
The need to engage boys in gender-transformative relationships and sexuality education (RSE) to reduce adolescent pregnancy is endorsed by the World Health Organization and the United Nations Educational, Scientific and Cultural Organization.

Objectives
To evaluate the effects of If I Were Jack on the avoidance of unprotected sex and other sexual health outcomes.

Design
A cluster randomised trial, incorporating health economics and process evaluations.

Setting
Sixty-six schools across the four nations of the UK.

Participants
Students aged 13–14 years.

Intervention
A school-based, teacher-delivered, gender-transformative RSE intervention (If I Were Jack) versus standard RSE.

Main outcome measures
Self-reported avoidance of unprotected sex (sexual abstinence or reliable contraceptive use at last sex) after 12–14 months. Secondary outcomes included knowledge, attitudes, skills, intentions and sexual behaviours.

Results
The analysis population comprised 6556 students: 86.6% of students in the intervention group avoided unprotected sex, compared with 86.4% in the control group {adjusted odds ratio 0.85 [95% confidence interval (CI) 0.58 to 1.26], p = 0.42}. An exploratory post hoc analysis showed no difference for sexual abstinence [78.30% intervention group vs. 78.25% control group; adjusted odds ratio 0.85 (95% CI 0.58 to 1.24), p = 0.39], but more intervention group students than control group students used reliable contraception at last sex [39.62% vs. 26.36%; adjusted odds ratio 0.52 (95% CI 0.29 to 0.920), p = 0.025]. Students in schools allocated to receive the intervention had significantly higher scores on knowledge [adjusted mean difference 0.18 (95% CI 0.024 to 0.34), p = 0.02], gender-equitable attitudes and intentions to avoid unintended pregnancy [adjusted mean difference 0.61 (95% CI 0.16 to 1.07), p = 0.01] than students in schools allocated to receive the control. There were positive but non-significant differences in sexual self-efficacy and communication skills. The total mean incremental cost of the intervention compared with standard RSE was £2.83 (95% CI –£2.64 to £8.29) per student. Over a 20-year time horizon, the intervention is likely to be cost-effective owing to its impact on unprotected sex because it would result in 379 (95% CI 231 to 477) fewer unintended pregnancies, 680 (95% CI 189 to 1467) fewer sexually transmitted infections and a gain of 10 (95% CI 5 to 16) quality-adjusted life-years per 100,000 students for a cost saving of £9.89 (95% CI –£15.60 to –£3.83).

Limitations
The trial is underpowered to detect some effects because four schools withdrew and the intraclass correlation coefficient (0.12) was larger than that in sample size calculation (0.01).

Conclusions
We present, to our knowledge, the first evidence from a randomised trial that a school-based, male engagement gender-transformative RSE intervention, although not effective in increasing avoidance of unprotected sex (defined as sexual abstinence or use of reliable contraception at last sex) among all students, did increase the use of reliable contraception at last sex among students who were, or became, sexually active by 12–14 months after the intervention. The trial demonstrated that engaging all adolescents early through RSE is important so that, as they become sexually active, rates of unprotected sex are reduced, and that doing so is likely to be cost-effective.

Future work
Future studies should consider the longer-term effects of gender-transformative RSE as students become sexually active. Gender-transformative RSE could be adapted to address broader sexual health and other settings.

Trial registration
This trial is registered as ISRCTN10751359.