Hypothetical mechanisms driving physical activity levels in ethnic minority groups living in Europe: a systematically identified evidence-based conceptual systems model

Background: In Europe, physical activity levels tend to be lower in ethnic minority groups than the general population. Interventions and policies based on research examining isolated determinants of physical activity have had limited success in increasing physical activity levels. This study used systems dynamics theory and the capability approach theoretical framework to develop a conceptual model of how individual characteristics, institutional and physical environments and the migration context may interact to promote or hinder physical activity in ethnic minority groups living in Europe. Methods: A systematic update of Langøien et al.’s 2017 review of the determinants of physical activity in ethnic minority groups living in Europe was conducted. Our target population included individuals of all ages who reported a familial migration background from any low- and middle-income countries or belonging to minority indigenous population in Europe. Outcomes pertaining to non-work related physical activity of light, moderate or vigorous intensity performed in any setting were included. Included studies provided an evidence base from which to derive the causal loop diagrams comprising our conceptual model. Sub-system causal loop diagrams were interpreted in co-author review sessions to explicate non-linear system mechanisms, such as reinforcing and balancing feedback loops. Results: Forty-one studies were identified, of which the majority was qualitative. The conceptual model consisted of 4 causal loop diagrams relating to psychosocial constructs; sociocultural constructs; health and health communication and social and material resources, in interaction with environmental/migration context. Four hypothetical mechanisms were identified, e.g. hypothesizing that participation in organised activities leads to increased self-efficacy, thereby enabling further participation. Conclusions: This study contributes an evidence-based conceptual systems model which elucidates how low levels of physical activity in ethnic minority groups in Europe could be supported by reinforcing and balancing mechanisms involving factors relating to physical and institutional environments, migration context and individuals. A pluralistic approach to literature review, integrating complexity methods such as CLDs into more conventional systematic literature review, supports novel insights into how factors could interact to support persistently low levels of activity, moving beyond the identification of potential relationships between isolated factors to indicating the ways in which these relationships are sustained and could be modified by intervention or policy.