A hybrid implementation-effectiveness study of a school-based intervention for promoting health and well-being in low-resource settings: the ISOBAR study protocol

Introduction:
School-based interventions can improve adolescent health outcomes and tackle the growing burden of non-communicable diseases (NCDs) in low-and-middle-income countries (LMICs). Results to date are variable, partly due to lack of cultural adaptation of Westernised models and limited focus on implementation processes. The aim of the ISOBAR project is to develop, implement, and test a school-based intervention to address the emergence of mental and physical (i.e., nutritional, physical inactivity) health problems in LMICs. The three-stage intervention comprises (1) assessment for mental and physical health problems, (2) universal health literacy, and (3) indicated counselling.

Methods and analysis:
The ISOBAR multi-site project comprises three phases: (1) pre-intervention (co-development and cultural adaptation of the intervention); (2) implementation of the intervention; and (3) post-intervention evaluation. The intervention will be delivered using a staggered roll-out design to introduce the intervention sequentially to three schools per site (nine in total) in Chennai, Gujarat (India), and Ibadan (Nigeria). Each school will receive the intervention by the end of the study period. Local teams will recruit 200 adolescents per school (Total n=1, 800). All adolescents (in intervention and control conditions) will be assessed for mental health/behavioural problems and nutritional/weight problems at baseline. Adolescents in the intervention school will receive the universal health literacy intervention (main cohort), and those adolescents reaching pre-determined thresholds on mental health and/or nutritional indices (sub-cohort) will be referred to school-based counselling support. A suite of assessments will be conducted throughout the study period including: (1) intervention effectiveness (e.g., impact on help-seeking, weight, and mental health and behavioural outcomes); (2) implementation processes (e.g., facilitators and barriers) and outcomes (e.g., acceptability, appropriateness, sustainability); and (3) cost-effectiveness.

Ethics and dissemination:
The study was approved by the University of Warwick’s Biomedical and Scientific Research Ethics Committee (BSREC 36/23-24) and the institutional ethics committees of all participating sites. Research findings will be disseminated through peer reviewed scientific publications, public announcements in local communities, policy briefings, print and online media, and institutional and professional social media accounts and websites.

Highlights:
• The ISOBAR study will develop a bespoke three-stage composite school-based physical and mental health intervention, which is culturally adapted to each study region.
• Intervention development and delivery is grounded in co-production to ensure suitability to setting and recipients.
• ISOBAR will build research capacity for future studies in LMICs including in implementation science and health economic evaluation.
• Due to logistical and ethical considerations, we are unable to conduct a randomised controlled trial meaning causal inference will be limited.
• For ethical reasons, students in the control condition will be provided guidance and signposting to local services, which might ‘dilute’ the effect of the intervention.