Table 1.
Independent predictors of risk for PPCs identified in the logistic regression model (ARISCAT score)
| Multivariate analysis OR (95% CI) n = 1.624* |
β | Risk scorea | |
|---|---|---|---|
| Age, years | |||
| ≤ 50 | 1 | ||
| 51–80 | 1.4 (0.6–3.3) | 0.331 | 3 |
| > 80 | 5.1 (1.9–13.3) | 1.619 | 16 |
| Preoperative SpO2, % | |||
| ≥ 96 | 1 | ||
| 91–95 | 2.2 (1.2–4.2) | 0.802 | 8 |
| ≤ 90 | 10.7 (4.1–28.1) | 2.375 | 24 |
| RTI in preceding month | 5.5 (2.6–11.5) | 1.698 | 17 |
| Preoperative anemia (Hb ≤ 10 g/dL) | 3.0 (1.4–6.5) | 1.105 | 11 |
| Surgical incision | |||
| Peripheral | 1 | ||
| Upper abdomen | 4.4 (2.3–8.5) | 1.480 | 15 |
| Intrathoracic | 11.4 (4.9–26.0) | 2.431 | 24 |
| Duration of surgery, hours | |||
| ≤ 2 | 1 | ||
| > 2–3 | 4.9 (2.4–10.1) | 1.593 | 16 |
| > 3 | 9.7 (4.7–19.9) | 2.268 | 23 |
| Emergency procedure | 2.2 (1.0–4.5) | 0.768 | 8 |
Three patients were excluded because of a missing value for some variables. Logistic regression model constructed with the development subsample, c-index = 0.90; Hosmer-Lemeshow chi-square test = 7.862; P = 0.447
CI confidence interval, Hb hemoglobin, OR odds ratio, PPC postoperative pulmonary complications, RTI respiratory tract infection, SpO2 oxyhemoglobin saturation by pulse oximetry (breathing room air in the supine position)
aSimplified risk score was the sum of each logistic regression coefficient (β) multiplied by 10, after rounding off