Universal Primary School Interventions to Improve Child Social–Emotional and Mental Health Outcomes: A Systematic Review of Economic Evaluations

Primary schools are key settings for social–emotional and mental health promotion. Reviews have assessed the effectiveness of primary school interventions delivered universally to all pupils for improving child social–emotional and mental health outcomes. This is the first study to review economic evaluations of such interventions and their value for money, which is key for informing policy. Peer-reviewed English language publications were systematically searched from database inception dates until 17 October 2022. We included economic evaluations of universal primary school interventions, or interventions with a universal component, to improve social–emotional and mental health outcomes in primary school children—regardless of evaluation methods or location. Key data and results were extracted from included studies for descriptive and narrative synthesis. Extracted costs were converted to International Dollars (Int$) and inflated to the year 2021. The reporting quality of included studies was appraised using the 2022 CHEERS checklist. Our review was prospectively registered on PROSPERO (CRD42020190148) and funded by the UK Economic and Social Research Council (ES/T005149/1). A total of 25 economic evaluations were included for analysis in our review. Full economic evaluations combining both costs and outcomes comprised 20 of the 25 evaluations, of which 16 used comparable outcomes. The remaining five economic evaluations were cost analyses (partial). Study quality varied substantially and was higher amongst full economic evaluations. Evaluated interventions consisted primarily of programmes and curricula (n = 9) and universal interventions combining a targeted component (n = 5), amongst other intervention types such as teacher practices (n = 3). Average annual costs per child varied substantially (Int$18.7-Int$83,656) across intervention types. Universal interventions combining a targeted component were the least costly (Int$26.9-Int$66.8), along with an intervention designed to improve school operational culture (Int$46.0), and most of the programmes and curricula evaluated (Int$21.4-Int$396). All except for one of the 16 full economic evaluations using comparable outcomes found interventions were cost-effective (cost-saving–Int$25,463/QALY) relative to country cost-effectiveness thresholds or yielded positive returns on investment (Int$1.31–11.55 for each Int$1 invested) compared with usual practice. We identified several low-cost interventions that likely provide good value for money and should be considered by policymakers in high-income countries. However, there is a need for more economic evaluations in low- and middle-income countries, and a need to improve study reporting quality and better value outcomes more generally.