Table 3.
Threshold effect analysis
| Models | Unadjusted model | Adjusted model | ||
|---|---|---|---|---|
| Unadjusted HR (95% CI) | P | Adjusted HR (95% CI) | P | |
| Model I | ||||
| One line slope | 0.88 (0.82–0.94) | <0.001 | 0.82 (0.76–0.88) | <0.001 |
| Model II | ||||
| Turning point (K1) | ||||
| <9.0 slope 1 | 0.38 (0.34–0.43) | <0.001 | 0.42 (0.37–0.48) | <0.001 |
| >9.0 slope 2 | 1.26 (1.19–1.34) | <0.001 | 1.12 (1.04–1.20) | 0.002 |
| LRT | <0.001* | <0.001* | ||
Data are presented as HR (95% CI) and P value.
*Indicates that model II is significant different from model I. Model I, linear analysis; model II, nonlinear analysis. Logarithmic likelihood ratio test (P < 0.05 means model II is significantly different from model I, which indicates a nonlinear association). The adjusted variables are the same as those in model III of multiple Cox regression.
CI, confidence interval; HR, hazard ratio; LRT, logarithmic likelihood ratio test.