Table 4.

Analysis of threshold effect and saturation effect.

PHR	Adjusted β (95% CI), P value
Model 1
A straight-line effect	1.24 (1.13, 1.35) < 0.001
Model 2
Fold points (K)	281.53
< K-segment effect 1	1.55 (1.27, 1.89) < 0.001
< K-segment effect 2	1.10 (0.97, 1.24) 0.144
Effect size difference of 2 versus 1	0.71 (0.54, 0.94) 0.015
Equation predicted values at break points	4.13 (3.99, 4.27)
Log likelihood ratio tests	0.017