TABLE 1.

Equations for Estimation of Physiologic Ability and Surgical Stress (E‐PASS) scores: preoperative risk score (PRS), surgical stress score (SSS), and comprehensive risk score (CRS)

1. PRS = −0.0686 + 0.00345X1 + 0.323X2 + 0.205X3 + 0.153X4 + 0.148X5 + 0.0666X6

X1, age; X2, presence (1) or absence (0) of severe heart disease; X3, presence (1) or absence (0) of severe pulmonary disease; X4, presence (1) or absence (0) of diabetes mellitus; X5, performance statusindex (0‐4); X6, American Society of Anesthesiologists physiological status classification (1‐5)

Severe heart disease was defined as heart failure of New York Heart Association Class III or IV, or severe arrhythmia requiring mechanical support. Severe pulmonary disease was defined as any condition with a %VC of less than 60% and/or a FEV1.0% of less than 50%. Performance status index was based on the definition by Eastern Cooperative Oncology Group.

2. SSS = −0.342 + 0.0139X1 + 0.0392X2 + 0.352X3

X1, blood loss/body weight (g/kg); X2, operation time (h); X3, extent of skin incision (0: minor incisions for laparoscopic or thoracoscopic surgery[including scope‐assisted surgery]; 1: laparotomy or thoracotomy alone; 2: both laparotomy and thoracotomy)

3. CRS = −0.328 + 0.936 (PRS) + 0.976 (SSS)

FEV, forced expiratory volume; VC, vital capacity.