Contextual factors influencing the integration of physical activity policy, systems, and environmental interventions in the cooperative extension system: a systematic review

BACKGROUND: Physical activity policy, systems, and environmental changes (PSEs) are effective but complex public health interventions. PSEs are increasingly being implemented through Cooperative Extension, a national system historically focused on individual-level direct education. Researchers have begun conducting contextual inquiry studies, but the extent to which they have matched barriers and facilitators to specific implementation strategies is unknown. This study seeks to understand common barriers and facilitators to integrating physical activity PSEs in Extension and identify implementation strategies selected in response. METHODS: A systematic review was conducted in June 2025 using three databases and two Extension-specific journals, with search terms focused on Extension; barriers, facilitators, and contextual factors; PSEs; and physical activity. Studies were included if they (1) were original, peer-reviewed articles, theses, or dissertations, (2) took place within Extension, (3) investigated integration of physical activity PSEs, (4) included barriers, facilitators, or contextual factors, (5) were in English, and (6) were published from 2014 to present. Two authors independently reviewed titles and abstracts for inclusion/exclusion, reviewed full text of remaining articles, and extracted data based on the Implementation Research Logic Model. Frequencies and proportions were calculated to tabulate data. RESULTS: Thirteen studies met inclusion criteria. Outcomes of interest were most commonly implementation (n = 9, 69%), adoption (n = 3, 23%), and maintenance (n = 3, 23%). Contextual inquiry was most commonly based on the Consolidated Framework for Implementation Research (n = 5, 38%) or no framework (n = 5, 38%). Studies using a framework predominantly collected data on the individuals (n = 6, 46%) or outer setting (n = 6, 46%) domains. Common barriers were individual capability, local conditions, and intervention complexity (each n = 6, 46%). Common facilitators were partnerships and connections (n = 7, 54%) and individual capability (n = 6, 46%). Most studies (n = 8, 62%) provided recommendations based on findings, although these were not explicitly labeled as implementation strategies. CONCLUSIONS: Results provide implications for improving contextual inquiry and implementation strategy selection in Extension. Contextual inquiry should be based on a determinant framework to understand multi-level influences on PSE integration. Otherwise, critical barriers within the inner setting may be overlooked. Specific matching processes should be used to engage key individuals in selecting implementation strategies that address specific barriers.