ParentApp for Teens in Tanzania Optimisation Trial


A pragmatic cluster randomised factorial trial to optimise caregiver engagement in ParentApp for Teens, an app-based adaptation of the in-person Parenting for Lifelong Health for Adolescents programme. A 2x2x2 multifactorial experimental design will be used to to examine the effectiveness, cost-effectiveness, and feasibility/acceptability of three intervention components aimed at enhancing engagement: A) Support (self-guided/moderated WhatsApp groups), B) App design (sequential workshops/non-sequential modules), and C) Digital literacy training (on/off). The study will be conducted amongst low-income caregivers of adolescents aged 10 to 17 years in Tanzania.


Violence against children and adolescents is a pervasive global problem, but it is particularly acute in low- and middle-income countries. Parenting interventions have shown promise in reducing violence and maltreatment, but in-person interventions are often expensive and inaccessible to at-risk families. Digital interventions present a scalable and cost-effective alternative, yet engaging families is a substantial implementation challenge. This study builds on the feasibility and acceptability piloting of ParentApp for Teens in South Africa and Tanzania.


Guided by the Multiphase Optimisation Strategy (MOST) framework, this study aims to identify the most effective, cost-effective and feasible/acceptable engagement package for ParentApp for Teens, targeting vulnerable caregivers of adolescents ages 10 to 17 years in Tanzania.

Primary objective

  1.  To identify which of the selected component levels contribute meaningfully to improvements in the primary engagement outcomes (overall number of app-opens, proportion of sessions completed, proportion of home practice activities attempted).
  2. To identify which of the selected component levels contribute meaningfully to improvements in the secondary engagement outcomes (overall time spent on app, proportion of sessions started, number of ParentPoints logged).


Secondary objectives

  1. To conduct exploratory analyses to examine whether there are any interaction effects between components on primary and secondary engagement outcomes.
  2. To conduct exploratory analyses of the potential impact of components and combination of component levels on caregiver behavioural outcomes (e.g., child maltreatment, positive parenting, parental communication about sexual abuse prevention).
  3. To conduct exploratory analyses to examine whether caregiver baseline characteristics (e.g., gender, age, financial stress and food insecurity, caregiver stress and depression, and parenting behaviour) are potential moderators of component effectiveness. 
  4. To estimate the incremental cost-effectiveness of component levels delivered during programme implementation.
  5. To qualitatively understand participant perspectives on the feasibility and acceptability of the component levels and the overall challenges and enablers of engaging with ParentApp.
  6. To identify the most effective, cost-effective, and feasible/acceptable combination of component levels to be tested further in an RCT in 2023.


Study Setting

The study will take place in peri-urban and urban regions of Mwanza City, Tanzania in collaboration with Tanzania’s National Institute for Medical Research (NIMR) and local NGO Investing in Children and Strengthening their Societies (ICS).


Study Significance and Impact

This study will be the first to optimise engagement in a parenting intervention delivered via an app in a low- and middle-income country. By examining the role of human support, app design, and a digital literacy training in reducing barriers to programme participation, this study promises to provide key insights into engagement and effectiveness whilst tailoring to vulnerable population needs, delivery challenges, and best-practises for scale-up. Findings will be used to inform the evaluation of the optimised app in a subsequent randomised controlled trial.