Evaluating physical activity interventions for socioeconomically disadvantaged adults through the RE-AIM framework: A systematic review of experimental and non–/quasi-experimental trials

The promotion of physical activity in people from lower social strata is a public health priority. Previous reviews of physical activity interventions among socioeconomically disadvantaged adults have focused on intervention effectiveness without considering their translation into practice. This review utilised the RE-AIM framework (Reach, Efficacy/Effectiveness, Adoption, Implementation, Maintenance) to (1) evaluate the extent to which experimental and non–/quasi-experimental trials of interventions to promote physical activity among socioeconomically disadvantaged adults report on issues of internal and external validity and (2) to provide recommendations for future intervention studies. Four databases were searched through June 2021. We included studies published in English or German since 2000 that tested physical activity interventions for socioeconomically disadvantaged adults. Two researchers coded all studies using a validated RE-AIM data extraction tool with 61 indicators referring to internal and external validity. Binary coding (yes = 1/no = 0) was applied to calculate the number and percentage of studies reporting each of the indicators. We included 39 studies of which 22 were non–/quasi-experimental trials. Indicators of reach were most frequently reported (59.2%), followed by implementation (38.9%) and efficacy/effectiveness (28.9%). Dimensions related to external validity were least frequently reported (adoption: 21.9%, maintenance: 17.8%). Few differences were found between experimental and non–/quasi-experimental trials. Analysis showed overall poor reporting of components related to internal and external validity. We recommend that future research should increase attention on reporting indicators of internal and external validity to facilitate their translation and implementation into real world settings. Trial registration: The review was registered with PROSPERO (CRD42021283688).