Association between socioeconomic status, lifestyle factors and mortality: A scoping review

Lifestyle factors have been widely discussed as potential mediators of the association between socioeconomic status (SES) and health outcomes. However, no comprehensive review has synthesized existing evidence on the mediating role of lifestyle factors in the association of SES with all-cause mortality and cancer-specific mortality. Therefore, we conducted a scoping review to sum up current evidence and highlight research gaps.

We systematically searched PubMed, EMBASE, and Web of Science from database inception to March 31, 2026 for observational studies that explicitly assessed the mediating role of lifestyle factors in the associations between SES and all-cause mortality or cancer-specific mortality.

Twenty-five longitudinal studies published between 2008 and 2025 were included, predominantly from high-income countries. The median proportions of the associations between SES and mortality mediated by lifestyle factors were modest, ranging from 5.4% to 28.0% for all-cause mortality and from 10.7% to 25.6% for cancer-specific mortality, with substantial heterogeneity across SES indicators, population subgroups, lifestyle measurement approaches, and analytic methods. Smoking consistently showed the strongest mediating role, whereas BMI contributed minimally. Studies using repeated or non-baseline assessments of lifestyle tended to report larger mediation effects.

There is evidence that lifestyle factors (in particular smoking habits) partially mediate the association between SES and all-cause and cancer-specific mortality. However, the magnitude of this mediation is highly sensitive to measurement strategies and study context. Future studies should adopt longitudinal and life-course designs with repeated measures of SES and lifestyle factors, and expand research to low- and middle-income countries to provide globally relevant evidence.