Low-income groups and behaviour change interventions: a review of intervention content, effectiveness and theoretical frameworks

Background: Interventions to change health-related behaviours have potential to increase health inequalities. Methods: This review investigated the effectiveness of interventions targeting low-income groups to reduce smoking or increase physical activity and/or healthy eating. Of 9766 papers identified by the search strategy, 13 met the inclusion criteria. Intervention content was coded into component technique and theoretical basis, and examined as a potential source of effect heterogeneity. Results: Interventions were heterogeneous, comprising 4-19 techniques. Nine interventions had positive effects, seven resulted in no change and one had an adverse effect. Effective interventions had a tendency to have fewer techniques than ineffective interventions, with no evidence for any technique being generally effective or ineffective. Only six studies cited theory relative to intervention development, with little information about how theory was used and no obvious association with intervention content or effect. Conclusion: This review shows that behaviour change interventions, particularly those with fewer techniques, can be effective in low-income groups, but highlights the lack of evidence to draw on in informing the design of interventions for disadvantaged groups.