Table 8 The result of the two-piecewise Cox regression model and linear regression model

Renal prognosis (HR,95%CI, P)

Fitting model by two-piecewise Cox regression

 Inflection point of Hb

8.6 g/dL

  ≤ 8.6 g/dL

1.257 (0.841, 1.878) 0.2650

  > 8.6 g/dL

0.789 (0.715, 0.870) < 0.0001

P for log-likelihood ratio test

0.026

Renal function decline(β,95%CI, P)

Fitting model by two-piecewise linear regression

 Inflection point of Hb

15.5 g/dL

  ≤ 15.5 g/dL

-0.551 (-0.920, -0.182) 0.0035

  > 15.5 g/dL

1.527 (-0.830, 3.883) 0.2045

 P for log-likelihood ratio test

0.096