Table 3.
Variables included in the multivariable adjusted, multilevel Cox proportional hazards model before time-varying stratification of complication. Random effects components were country nested within study, and the value represents the standard deviation of the intercept for the log hazard ratio. ∗P-value <0.05. P-value for global Schoenfeld test=0.03. ASA, American Society of Anesthesiologists; CI, confidence interval; COPD, chronic obstructive pulmonary disease.
| Feature | Adjusted hazard ratio (95% CI) | z |
|---|---|---|
| Complication within 30 days | 1.94 (1.53–2.46) | 5.55∗ |
| Age (1 yr increment) | 1.04 (1.03–1.05) | 7.38∗ |
| Sex: female vs male | 0.73 (0.58–0.93) | –2.98∗ |
| ASA physical status: 2 vs 1 | 1.63 (0.9–2.95) | 1.64 |
| ASA physical status: 3 vs 1 | 3.15 (1.71–5.8) | 3.72∗ |
| ASA physical status: 4 vs 1 | 6.11 (2.85–13.13) | 4.72∗ |
| Smoking status: current vs not current | 1.45 (1.04–2.02) | 6.2∗ |
| Operative severity: low vs high | 1.07 (0.73–1.56) | 0.41 |
| Operative severity: moderate vs high | 1.15 (0.89–1.48) | 1.07 |
| Surgery for cancer | 2.89 (2.24–3.72) | 8.17∗ |
| Coronary artery disease | 0.36 (0.17–0.74) | –2.58∗ |
| Cardiac failure | 0.65 (0.3–1.38) | –0.84 |
| Cancer | 1.59 (0.78–3.23) | 1.72 |
| Diabetes mellitus | 0.42 (0.2–0.86) | –2.14∗ |
| Stroke | 1.25 (0.84–1.86) | 1.08 |
| COPD | 0.48 (0.23–1) | –1.67 |
| Chronic kidney disease | 0.59 (0.29–1.23) | –1.23 |
| Number of diseases: 1 vs 0 | 2.53 (1.21–5.28) | 2.10∗ |
| Number of diseases: 2 vs 0 | 5.64 (1.4–22.68) | 2.24∗ |
| Number of diseases: ≥3 vs 0 |
15.33 (1.72–136.85) |
2.15∗ |
|
Random effects components Study/country Country |
Standard deviation 0.65 1.20 |
Variance 0.42 1.45 |