Health behavior interventions among people with lower socio-economic position: a scoping review of behavior change techniques and effectiveness

Behavior change interventions can unintendedly widen existing socio-economic health inequalities. Understanding why interventions are (in)effective among people with lower socio-economic position (SEP) is essential. Therefore, this scoping review aims to describe what is reported about the behavior change techniques (BCTs) applied within interventions and their effectiveness in encouraging physical activity and healthy eating, and reducing smoking and alcohol consumption according to SEP. A systematic search was conducted in 12 electronic databases, and 151 studies meeting the eligibility criteria were included and coded for health behavioral outcomes, SEP-operationalization, BCTs (type and number) and effectiveness. Findings suggest that approaches for measuring, defining and substantiating lower SEP vary. Current studies of behavior change interventions for people of different SEP do not systematically identify BCTs, making systematic evaluation of BCT effectiveness impossible. The effectiveness of interventions is mainly evaluated by overall intervention outcomes and SEP-moderation effects are mostly not assessed. Using different SEP-operationalizations and not specifying BCTs hampers systematic evidence accumulation regarding effective (combinations of) BCTs for the low SEP population. To learn which BCTs effectively improve health behaviors among people with lower SEP, future intervention developers should justify how SEP is operationalized and must systematically describe and examine BCTs.