A blended digital parenting intervention for the prevention of sexual violence, exploitative sex, and maltreatment of children at scale in Tanzania: a cluster-randomised, controlled trial

BACKGROUND: Childhood sexual, physical, and verbal violence are global public health priorities, affecting 1 billion children each year. ParentApp integrates sexual violence prevention into WHO-UNICEF's open-access Parenting for Lifelong Health programme, using innovative blended digital delivery. We aimed to test the efficacy of ParentApp in preventing sexual violence and maltreatment against adolescent-aged children and improving preventive mechanisms such as family mental health and adolescent-caregiver relationships. METHODS: This cluster-randomised, controlled trial was conducted in 80 Tanzanian sub-wards. Participants were primary caregivers aged 18 years and older and their adolescents (aged 10-17 years). Sub-wards were randomly assigned (1:1) to receive either ParentApp (intervention group) or a control WASHApp programme. Clusters were randomly assigned in blocks of six, stratified by urban versus rural location. Statisticians carrying out randomisation and data analysts were masked; it was not possible to mask participants or researchers. Intervention groups received a low-cost Android phone installed with ParentApp, a 12-module offline-first app, with one in-person orientation session and remote support via WhatsApp group chats, at a delivery cost of US$6 per family at scale, or $10 with 20% smartphone provision. Control groups received a low-cost Android phone installed with WASHApp, a 12-module offline-first app for water, sanitation, and hygiene, with one in-person orientation session. The primary outcomes were adolescent sexual violence victimisation and maltreatment and high-risk situations for sexual violence, assessed in all participants irrespective of uptake and engagement at 5 months and 18 months post-baseline. The trial was registered on March 14, 2023, with OSF (https://osf.io/t9fxz) and is completed. FINDINGS: Between May 11 and Oct 9, 2023, 2692 caregiver-adolescent dyads were screened for study eligibility; 2396 adolescents (1217 [50·8%] female and 1179 [49·2%] male) and 2396 caregivers (1795 [74·9%] female and 601 [25·1%] male) were recruited. 2145 (89·5%) adolescents and 2252 (94·0%) caregivers were retained in the study and included in analyses at 18 months. Adolescent girls in ParentApp clusters had a substantial reduction in past-month sexual violence victimisation compared with those in control clusters (incidence rate ratio [IRR] 0·43 [95% CI 0·21-0·86]; p=0·018), with no effect for boys (1·21 [0·59-2·43]; p=0·60). Past-month maltreatment (physical abuse, verbal abuse, and neglect) was lower in ParentApp clusters than in control clusters (adolescent report IRR 0·92 [0·88-0·96]; p<0·0001, caregiver report 0·87 [0·82-0·92]; p<0·0001). Past-month exposure to high-risk situations for sexual violence was lower in ParentApp clusters than in control clusters (adolescent girls IRR 0·87 [0·77-0·97]; p=0·012, adolescent boys 0·85 [0·79-0·91]; p<0·0001, caregiver report 0·81 [0·75-0·88]; p<0·0001). There were no reported adverse events. INTERPRETATION: A low-cost blended digital parenting programme in countries such as Tanzania could simultaneously reduce childhood sexual violence (for girls) and maltreatment and sexual violence risk situations (for girls and boys).