Table 2.
Multivariable Cox regression analyses based on the selected predictors of disability-free survival. Estimates were pooled across multiple imputed data sets using Rubin’s rule
| Male | Female | |||||
|---|---|---|---|---|---|---|
| Characteristic | HR | 95% CI | p-value | HR | 95% CI | p-value |
| Age (+5 years) | 1.49 | 1.38, 1.60 | <0.001 | 1.50 | 1.40, 1.61 | <0.001 |
| 3MS (+5 units) | 0.74 | 0.69, 0.79 | <0.001 | 0.68 | 0.63, 0.72 | <0.001 |
| Gait speed (+0.2 m/s)* | 0.82 | 0.77, 0.88 | <0.001 | <0.001 | ||
| 0.5 vs. 1.0 m/s | 1.64 | 1.38, 1.95 | 2.71 | 2.20, 3.33 | ||
| 1.5 vs. 1.0 m/s | 0.61 | 0.51, 0.73 | 0.80 | 0.56, 1.15 | ||
| Grip strength | 0.92 | 0.88, 0.96 | <0.001 | 0.91 | 0.85, 0.97 | 0.003 |
| Current smoking | 1.95 | 1.51, 2.52 | <0.001 | … | … | … |
| BMI (kg/m2)* | <0.001 | <0.001 | ||||
| 25 vs. 30 kg/m2 | 1.15 | 1.05, 1.26 | 1.11 | 1.03, 1.19 | ||
| 35 vs. 30 kg/m2 | 1.17 | 1.02, 1.35 | 1.29 | 1.17, 1.41 | ||
| eGFR (mL/min per 1.73 m2)* | <0.001 | … | … | … | ||
| 40 vs. 75 mL/min per 1.73 m2 | 1.61 | 1.26, 2.07 | ||||
| 90 vs. 75 mL/min per 1.73 m2 | 1.24 | 1.04, 1.49 | ||||
| CES-D ≥8 | … | … | … | 1.47 | 1.23, 1.77 | <0.001 |
| Diabetes | … | … | … | 1.30 | 1.06, 1.60 | 0.012 |
In the model for male participants, the effect of BMI and eGFR on not maintaining disability-free survival outcome were significantly nonlinear. In the model for female participants, the effects of BMI and gait speed on the outcome were significantly nonlinear. All non-linear relations were modelled with a restricted cubic spline function with 2 degrees of freedom. To simplify interpretation of the corresponding regression coefficients, only HRs for 2 derived contrasts for each predictor are given. p values for those predictors are based on overall Wald tests of the restricted cubic spline function. Abbreviations: HR hazard ratio, CI confidence interval