Why are anti-smoking health-information interventions less effective among low-socioeconomic status groups?

Issues: This paper identifies and synthesises explanations proposed in the literature for the (in)effectiveness of institutional anti-smoking health-information interventions (HII) among low-socioeconomic status (SES) adults in high-income countries. Approach: We searched eight databases for relevant papers from various disciplines: Studies published in English since 2009, on the effectiveness among low-SES adults of anti-smoking HIIs, aimed at changing knowledge/behaviour, and conducted by official institutions, were included. Through a scoping review, we synthesised: study design, SES indicator, intervention type, intervention source, study population, outcomes, low-SES effects, equity effects, proposed explanations and whether these were studied empirically. Key Findings: Thirty-eight studies were included in this scoping review. Seventeen suggested explanations for the (in)effectiveness of the HIIs in low-SES adults, but only nine assessed them empirically. Thematic analysis yielded six themes: message engagement, material conditions, cognition, risk perception, social environment and self-efficacy. Implications: Explanations for intervention results are not always present, and empirical evidence for explanations is often not provided. Including such explanations and testing their empirical merits in future research can provide the crucial information needed for developing more effective anti-smoking HIIs for low-SES adults. Conclusions: To our knowledge, this is the first review to explore the explanations proposed for why anti-smoking HIIs are (in)effective among low-SES adults. It contains insights for future studies aiming to provide empirical evidence on the causes of this (in)effectiveness, and concludes that such research is yet largely missing, but crucial to the quest for more effective and equitable anti-smoking interventions.