Table 1.

PICOSS criteria.

	Inclusion criteria	Exclusion criteria
Population	Young people that are disadvantaged or at risk people of poorer outcomes aged between 10 and 25.	Young people aged less than 10 or more than 25 or not disadvantaged or at risk of poorer outcomes.
Intervention	Summer employment programme: an out‐of‐school‐time programme that takes place during the summer months in whole or in part and includes a fixed‐term job placement. Summer education programme: an out‐of‐school‐time programme that takes place during the summer months in whole or in part, where content is majority administered through education‐focused instruction.	Programmes that do not fulfil the criteria of either a summer employment or summer education programme.
Comparison	Treatment as usual, another intervention, no intervention, or wait‐list control.	Studies that cover a population that is different in observable characteristics and that receive an alternative intervention not tracked by evaluation. Studies that mobilise non‐counterfactual measures except eligible studies of UK‐based interventions.
Outcome	Studies that examine: (1) violence and offending; (2) academic; (3) employment; (4) socio‐emotional; or (5) health outcomes.	Studies that examine other outcomes while not covering the outcome domains of interest. Studies that only consider health outcomes or health outcomes plus socio‐emotional outcomes that are direct consequences of health outcomes.
Study design	Randomised Controlled Trials (RCT) including individual and cluster level randomisation. Step‐Wedge designs with random time allocation. Non‐equivalent control group designs using parallel cohorts that adjust for baseline equivalence. Difference‐in‐Difference estimation. Interrupted time‐series. Synthetic control group methods. Studies based on: − covariate matching; − propensity score‐based methods; − doubly robust methodsa; − regression adjustment; − regression discontinuity designs; and − instrumental variable estimation. Qualitative studies and economic evaluations will be included if they are conducted as part of a qualifying study and will be used only to generate hypotheses, inform us about the interventions and populations, and inform or deepen our understanding of the quantitative findings. They will be included however if they are evaluating UK‐based interventions and are identified via the searches or recommended to this study by experts.	Non‐primary studies (except studies of this type that are evaluating UK‐based interventions), including: − literature reviews; − systematic reviews; − meta‐analysis; and − non‐primary QEDs. Studies without a valid counterfactual, including designs that do not include a parallel cohort that establish or adjust for baseline equivalence (except studies of this type that are evaluating UK‐based interventions), including: − single group pre‐post designs; − control group designs without matching in time and establishing baseline equivalence; − cross‐sectional designs; − non‐controlled observational (cohort) designs; − case‐control designs; − case studies/series; and − surveys.
Setting	Studies that are undertaken in high income countries, as defined by the World Bank (2023).	Studies that are not undertaken in high income countries, as defined by the World Bank (2023).
Other	Studies that are published in English.	Studies that are not published in English.
	Studies published since 2012 up to the end of 2022.	Studies published before 2012 or since 2023.

^a ‘Combines a form of outcome regression with a model for the exposure (i.e., the propensity score) to estimate the causal effect of an exposure on an outcome’ (Funk et al., 2011, p. 761)

Source: IES (2024).