Occupational and Nonoccupational Physical Activity and Their Association With All-Cause, Cardiovascular, and Cancer Mortality in US Adults: A Prospective Cohort Study from the NHANES 2007 to 2018

BACKGROUND: It remains unclear whether achieving the physical activity guidelines through occupational activity alone, nonoccupational activity alone, or combined occupational and nonoccupational activity has different health consequences. METHODS: Adults aged 18 years or older in the NHANES (National Health and Nutrition Examination Survey) from 2007 to 2018 were prospectively observed. Mortality data were acquired from the National Death Index through December 31, 2019. Time of self-reported occupational and nonoccupational activity was calculated. All-cause mortality was the primary outcome, with cardiovascular and cancer mortality as secondary outcomes. Cox proportional hazards models were used to analyze the association of occupational and nonoccupational activity with mortality. RESULTS: During a median follow-up of 6.92 years, 23 752 participants were included in our analysis, with 1367 deaths recorded, including 367 cardiovascular and 328 cancer deaths. Compared with inactive participants, those achieving recommended activity levels through occupational activity alone (hazard ratio [HR], 0.75 [95% CI, 0.60-0.94]), nonoccupational activity alone (HR, 0.58, [95% CI, 0.47-0.71]), or combined activity (HR, 0.43 [95% CI, 0.33-0.56]) had lower all-cause mortality. Additionally, those achieving recommended activity levels through nonoccupational activity alone (HR, 0.51 [95% CI, 0.36-0.71]) or combined activity (HR, 0.32 [95% CI, 0.20-0.57]) had lower cardiovascular mortality. However, occupational activity alone (HR, 0.89 [95% CI, 0.61-1.29]), nonoccupational activity alone (HR, 0.98 [95% CI, 0.66-1.46]), and combined activity (HR, 0.65 [95% CI, 0.38-1.11]) were not associated with cancer mortality. CONCLUSION: Achieving recommended activity levels through any domain was associated with lower all-cause mortality. Nonoccupational activity alone or combined activity was associated with lower cardiovascular mortality. Participants in occupational activity alone may benefit more if they also achieve recommended activity levels through nonoccupational activity.