The socioeconomic inequity in health is largely independent of unhealthy lifestyles in US and in UK

Main conclusions

Unhealthy lifestyles mediated a small proportion of the socioeconomic inequity in health in two large cohorts of adults, one in the US, the other in UK.

Type of study

Analysis of two cohort studies: 44 462 US adults aged at least 20 years from the NHANES (8 906 deaths for 11.2 years), and 399 537 UK adults aged 37-73 years from UK Biobank (22 309 deaths included 6903 CV deaths for 8.8-11.0 years). Analyses were done by classifying populations by socioeconomic status (SES: low, medium and high) and healthy lifestyle (never smoking, no heavy alcohol consumption, top third of physical activity and higher dietary quality). Compared with adults of high SES, those of low SES had higher risks of all-cause mortality (HR : 2.13; 95%CI : 1.90-2.38 in US NHANES and 1.96; 1.87- 2.06 in UK Biobank), CVD mortality (2.25; 2.00-2.53) and incident CVD (1.65; 1.52 to 1.79) in UK Biobank and the proportions mediated by lifestyle were 12.3% (10.7%-13.9%), 4.0% (3.5%- 4.4%),3.0% (2.5%-3.6%), and 3.7% (3.1%-4.5%), respectively. No significant interaction was observed between lifestyle and SES in US NHANES, whereas associations between lifestyle and outcomes were stronger among those of low SES in UK Biobank.

Main message for clinical practice

Healthy lifestyle promotion alone might not substantially reduce the socioeconomic inequity in health and other measures tackling social determinants of health are warranted.