Table 3.
Cox Regression Relating Survival to Frailty (FI): Model 1 and Model 2
| Model 1 (Continuous Frailty) | Model 2 (Categorical Frailty) | |||||
|---|---|---|---|---|---|---|
| Variable | Log HR (SE) | P > x2 | HR (95% CI) | Log HR (SE) | P > x2 | HR (95% CI) |
| FI | 5.10 (0.43) | <.001 | ||||
| FI × Cohort 2 | −2.36 | .005 | ||||
| FI ∆ 0.1 for cohort 1 | 0.51 (0.04) | <.001 | 1.67 (1.53, 1.81) | |||
| FI ∆ 0.1 for cohort 2 | 0.27 (0.07) | <.001 | 1.32 (1.14, 1.52) | |||
| FI (vulnerable vs mild) × Cohort 2 | −0.43 (0.28) | .13 | ||||
| FI for cohort 1 (vulnerable vs mild) | 0.57 (0.15) | <.001 | 1.76 (1.32, 2.36) | |||
| FI for cohort 2 (vulnerable vs mild) | 0.14 (0.24) | .56 | 1.15 (0.72, 1.83) | |||
| FI (moderate vs mild) * Cohort 2 | −0.65 (0.29) | .02 | ||||
| FI for cohort 1 (moderate vs mild) | 1.14 (0.15) | <.001 | 3.14 (2.33, 4.23) | |||
| FI for cohort 2 (moderate vs mild) | 0.50 (0.24) | .04 | 1.64 (1.02, 2.65) | |||
| FI (severe vs mild) × Cohort 2 | −0.99 (0.39) | .01 | ||||
| FI for cohort 1 (severe vs mild) | 2.05 (0.20) | <.001 | 7.74 (5.22, 11.47) | |||
| FI for cohort 2 (severe vs mild) | 1.05 (0.36) | .002 | 2.86 (1.48, 5.52) | |||
| Sex (female) | −0.82 (0.08) | <.001 | 0.44 (0.38, 0.52) | −0.81 (0.08) | <.001 | 0.46 (0.38, 0.52) |
| Cohort (2) FI | −0.78 (0.10) | <.001 | 0.46 (0.38, 0.56) | −0.97 (0.17) | <.001 | 0.38 (0.27, 0.53) |
Note: For frailty (FI) as a continuous measure the incremental change is 0.1 units. In Model 1, frailty is centered at the mean value and cohort mortality is assessed at that value. For Model 2, cohort mortality is assessed at mild frailty levels. The categories of frailty were based on four previously decided frailty classes, defined as mild (0–0.12), vulnerable (0.13–0.22), moderate (0.23–0.39), and severe (>0.40).