Risk of all-cause mortality is associated with multiple health-related lifestyle behaviors and does not differ between urban and rural areas in Korea.

Background/objectives: Urban-rural inequities in health and mortality exist in Korea, a highly centralized developed country. The potential impact of multiple health-related lifestyle behaviors on mortality and difference between urban and rural areas is not fully understood. This study aimed to investigate the effect of high-risk health behaviors on all-cause mortality among residents living in urban and rural in Korea.

Subjects/methods: Cross-sectional analyses were conducted on 8,298 adults aged 40 yrs and older from the Korea National Health and Nutrition Examination Survey 2013-2015. High-risk behaviors were defined as having poor diet quality, current smoking, high-risk drinking, or insufficient physical activity. Mortality status was linked to the Cause of Death data followed up to December 31, 2019. The associations between all-cause mortality and high-risk behaviors were evaluated using Cox proportional hazard regression models adjusted for age, sex, education, income, and survey year. Population attributable fractions (PAFs) were calculated, and effect modification analysis was conducted. Participants were stratified by residential area (urban or rural).

Results: During the follow-up (median: 5.4 yrs), 313 deaths occurred. A higher proportion of rural residents than urban residents engaged in multiple high-risk behaviors (28.9% vs. 22.6%; P < 0.0001). As individual factors, a greater risk of mortality was associated with poor diet quality, current smoking, and inadequate physical activity, and these tendencies persisted in rural residents, especially for diet quality. Multiple high-risk behaviors were positively associated with a higher risk of mortality in Koreans living in urban and rural areas. PAF (95% confidence interval) was 18.5% (7.35-27.9%) and 29.8% (16.1-40.2%) in urban and rural residents, respectively. No additive or multiplicative effect of the region was observed.

Conclusion: The higher prevalence of multiple high-risk lifestyle behaviors in rural residents may explain the higher mortality in rural areas compared to urban areas. Comprehensive public health policies to improve health-related behaviors in rural populations may be needed.