Predictivity of International Physical Activity Questionnaire Short Form for 5-Year Incident Disability Among Japanese Older Adults

Background: This study aimed to examine whether physical activity measured using the International Physical Activity Questionnaire Short Form (IPAQ-SF) can predict incident disability in Japanese older adults. Methods: Community-dwelling older adults participated in a prospective cohort survey. The time spent in moderate- to vigorous-intensity physical activity was assessed at the survey baseline using the IPAQ-SF. The participants were categorized into those who spent >= 150 minutes per week (physically active) or <150 minutes per week (physically inactive) in moderate- to vigorous-intensity physical activity. Incident disability was monitored through Long-Term Care Insurance certification during a follow-up lasting 5 years. Results: Among the 4387 analyzable participants (mean age = 75.8 y, 53.5% female), the IPAQ-SF grouped 1577 (35.9%) and 2810 (64.1%) participants as those who were physically active and inactive, respectively. A log-rank test showed a significantly higher incidence of disability among the inactive group of participants (P<.001). The Cox proportional hazards model showed that physically inactive participants had a higher risk of incident disability than the physically active ones did, even after adjusting for covariates (hazard ratio, 1.24; 95% CI, 1.07-1.45, P<.001). Conclusions: Older adults identified as physically inactive using the IPAQ-SF had a greater risk of developing disabilities than those identified as physically active. The IPAQ-SF seems to be appropriate to estimate the incidence risk of disability.