Effects of gender-transformative relationships and sexuality education to reduce adolescent pregnancy (The JACK trial): a cluster randomised trial

Maria Lohan, Aoibheann Brennan-Wilson , Rachael Hunter, Andrea Gabrio, Lisa McDaid, Honor Young, Rebecca French, Áine Aventin, Mike Clarke, Clíona McDowell, Danielle Logan, Sorcha Toase, Liam O'Hare, Chris Bonell, Katie Gillespie, Aisling Gough, Susan Lagdon, Emily Warren, Kelly Buckley, Ruth LewisLinda Adara, Theresa McShane, Julia Bailey, James White

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    The need to engage boys in gender-transformative relationships and sexuality education (RSE) to reduce adolescent pregnancy is endorsed by WHO. We aimed to test an intervention which used a gender-transformative approach to engage adolescents in RSE to prevent unprotected sex.

    This cluster-randomised trial with process and economic evaluations tested a school-based intervention entitled If I Were Jack versus standard RSE (control) for students (aged 14–15 years) in UK schools. Schools were randomly allocated (1:1) and masked to allocation at baseline. The primary outcome was self-reported avoidance of unprotected sex (sexual abstinence or use of reliable contraception at last sex) after 12–14-months. We analysed the data using intention-to-treat mixed effects regression models.

    Of 803 schools assessed for eligibility, 263 schools were invited by letter, of which 66 schools agreed to be randomly assigned, of which 62 schools completed follow-up. The trial was done between Feb 1, 2018, and March 6, 2020. 8216 students participated at baseline in 2018; 6561 (79·85%) provided 12–14 months follow-up. There was no significant difference in the primary outcome of avoidance of unprotected sex: 2648 (86·62) of 3057 in the intervention group avoided unprotected sex versus 2768 (86·41%) of 3203 in the control group (adjusted odds ratio [aOR] 0·85 [95% CI 0·58–1·26], p=0·42). Exploratory post-hoc analysis of the two components of the primary outcome showed that significantly more intervention students used reliable contraception at last sex compared with control students and there was no significant difference between the groups for sexual abstinence. No adverse events were reported.

    The intervention had a null effect on the primary outcome of preventing unprotected sex (increasing sexual abstinence or use of reliable contraception) in the whole student population. However, the results showed significant increases in use of reliable contraceptives for sexually active students. Engaging all young people early through RSE is important so that as they become sexually active, rates of unprotected sex are reduced.
    Original languageEnglish
    Pages (from-to)e626-e637
    Number of pages12
    JournalThe Lancet Public Health
    Issue number7
    Early online date29 Jun 2022
    Publication statusPublished (in print/issue) - 1 Jul 2022

    Bibliographical note

    Funding Information:
    This study was funded by the National Institute of Health Research Public Health Research programme (NIHR PHR 15/181/01). The views and opinions expressed herein are those of the authors and do not necessarily reflect those of the Public Health Research Programme, NIHR, NHS or the Department of Health. Queen's University Belfast (QUB) agreed to act as sponsor for the research. LMcD and RL were funded by the UK Medical Research Council and Chief Scientist Office of the Scottish Government Health and Social Care Directorates at the MRC–CSO Social & Public Health Sciences Unit, University of Glasgow (MC_UU_12017/11, SPHSU11; MC_UU_00022/3, SPHSU18). Intervention development was funded by the UK ESRC (RES-189-25-0300) together with the Health Services Executive of Ireland Crisis Pregnancy Programme and the Public Health Agency of Northern Ireland. The feasibility trial (ISRCTN99459996) was funded by the NIHR Public Health Research programme (15/181/01). The Scottish transferability study was funded by the UK MRC (MC_UU_12017/11) and the Scottish Government Chief Scientist Office (SPHSU11). The transferability study in Wales and England was funded by the Centre for the Development and Evaluation of Complex Interventions for Public Health Improvement, Cardiff University and University College London. Eimear Ruane-McAteer, Kim Appleton, Michelle Templeton, Rhonda Campbell, and Jaele Rollins were involved for a period of the study and made valuable contributions. Lisa Maguire, and Adam Fletcher contributed to early-stage proposal development.

    Publisher Copyright:
    © 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license


    • Adolescent
    • Female
    • Humans
    • Male
    • Pregnancy
    • Pregnancy in Adolescence - prevention & control
    • Schools
    • Sex Education - methods


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