Introduction: The social gradient in consumption behaviours has been suggestedto partly explain health inequalities. The majority of previous studies have onlyincluded baseline measurements and not considered potential changes in behav-iours over time. The study aimed to investigate the contribution of alcohol con-sumption and smoking to the social gradient in mortality and to assess whetherthe use of repeated measurements results in larger attenuations of the main asso-ciation compared to using single baseline assessments.

Methods: Longitudinal survey data from the population-based Stockholm PublicHealth Cohort from 2006 to 2014 was linked to register data on mortality until2018 for 13,688 individuals and analysed through Cox regression.

Results: Low socioeconomic position (SEP) was associated with increased mortal-ity compared with high SEP; hazard ratios 1.56 (95% CI 1.30–1.88) for occupa-tional status and 1.77 (95% CI 1.49–2.11) for education, after adjustment fordemographic characteristics. Using repeated measurements, alcohol consumptionand smoking explained 44% of the association between occupational status andall-cause mortality. Comparing repeated and baseline measures, the percentageattenuation due to alcohol consumption increased from 11% to 18%, whereas itremained similar for smoking (25–23%).

Discussion and Conclusions: Smoking and alcohol consumption explained alarge part of the association between SEP and mortality. Comparing results fromtime-fixed and time-varying models, there was an increase in overall percentageattenuation that was mainly due to the increased proportion explained by alcoholconsumption. Repeated measurements provide a better estimation of the contri-bution of alcohol consumption, but not smoking, for the association between SEPand mortality.