Prediction of Length of Stay Following Elective Percutaneous Coronary Intervention

Table 5

Relative risk comparing each risk group with the reference group with respect to LOS based on tree-structured prognostic classification.

Risk group	Testing data set
Very low (no heart failure and <70 years and without renal failure)	1.0
Low (no heart failure and ≥70 years and male)	1.26 (1.23, 1.30)
Moderate (no heart failure and ≥70 years and female)	1.48 (1.43, 1.54)
High (no heart failure and <70 years and with renal failure )	2.29 (2.06, 2.54)
Very high (heart failure present)	3.20 (3.05, 3.34)
LL*	−169549.66^†

*LL: log likelihood.
^†𝑃=0.002 comparing tree-structured prognostic classification with Wu et al.’s risk score suggests that Wu et al.’s model providing a better fit.