Physical Fitness and Device-Based Moderate-to-Vigorous Physical Activity and Risk of Long-Term Sickness Absence-A Prospective Cohort Study With 8-Year Follow-Up.

We examined the association of physical fitness (PF) and accelerometer-based moderate-to-vigorous intensity physical activity (MVPA) with long-term sickness absence (LTSA) incidence over an 8-year of follow-up in Finnish working-age population. Study data was based on Finnish population-based cross-sectional Health 2011 health examination survey's Physical Activity and Fitness sub-sample. Sample included 4821 over 18 years old adults, of whom 48% participated. Baseline MVPA was assessed using a hip-worn accelerometer over at least four consecutive days, while PF included assessments of cardiorespiratory and muscular fitness, and balance. MVPA and PF were categorized according to tertile cut points. Information of LTSA, covering all-cause, musculoskeletal, and mental health-related absences lasting more than 10 workdays, were derived from the Finnish Social Insurance Institution's register data. After excluding participants not at risk for LTSA due to old age or retirement, the analytical sample included 1464 participants. Associations were examined with negative binomial regression. After adjusting for key covariates and preceding LTSA, lower LTSA rates were observed among those with highest PF compared to lowest PF (IRR = 0.39; 95% CI 0.18-0.85) and with highest MVPA compared to lowest MVPA (IRR = 0.35; 95% CI 0.19-0.66). The associations were mainly similar regardless of chronic diseases or whether the cause of LTSA was a musculoskeletal or mental health condition. The associations became inconsistent over time, especially regarding physical activity. These results emphasize the important role of MVPA and PF as factors supporting work ability and preventing LTSA in general working-age population.