Figure 3.

Dose–response association between ST and FD. (A-C) shows the association between ST and FD among all participants (A), non-frail older adults (B), and frail older adults (C), modeled by restricted cubic splines. ST and MVPA were mutually adjusted, as well as baseline age, sex, district, living situation, marital status, education, equivalent income, body mass index, hypertension, dyslipidemia, heart disease, stroke, diabetes mellitus, cancer, alcohol drinking status, smoking status, lower back pain, knee pain, and frailty (in the stratified analyses (B,C), frailty was excluded from covariates). The reference value for the ST was 300 min/day. Solid lines indicate hazard ratios for FD. Dashed lines indicate 95% confidence intervals. FD = functional disability; METs = metabolic equivalent; MVPA = moderate-to-vigorous physical activity; ST = sedentary time.