Association between preoperative and postoperative COVID-19 and risk of postoperative complications
| Cases/total (%) | Postoperative complications | ||||||
| Model 1 | Model 2 | Model 3 | |||||
| OR (95% CI) | P value | OR (95% CI) | P value | OR (95% CI) | P value | ||
| Preoperative COVID-19 vs No COVID-19 | |||||||
| Time from surgery to diagnosis of COVID-19 | |||||||
| No COVID-19 | 103/959 (10.74) | Ref. | Ref. | Ref. | |||
| Pre-1w | 24/126 (19.05) | 2.21 (1.34, 3.64) | 0.002 | 2.42 (1.41, 4.15) | 0.001 | 2.67 (1.50, 4.78) | 0.001 |
| Pre-2w | 24/135 (17.78) | 2.03 (1.23, 3.33) | 0.005 | 2.26 (1.32, 3.87) | 0.003 | 2.14 (1.20, 3.80) | 0.010 |
| Pre-3w | 15/143 (10.49) | 1.09 (0.61, 1.96) | 0.76 | 1.14 (0.62, 2.09) | 0.68 | 1.27 (0.67, 2.39) | 0.46 |
| Pre-4w or more | 151/1467 (10.29) | 1.06 (0.81, 1.38) | 0.69 | 1.15 (0.86, 1.53) | 0.34 | 1.24 (0.92, 1.68) | 0.15 |
| Postoperative COVID-19 vs No COVID-19 | |||||||
| Time from surgery to diagnosis of COVID-19 | |||||||
| No COVID-19 | 103/959 (10.74) | Ref. | Ref. | Ref. | |||
| Post-1w | 33/172 (19.19) | 2.22 (1.43, 3.47) | <0.001 | 2.29 (1.41, 3.72) | 0.001 | 2.48 (1.48, 4.13) | 0.001 |
| Post-2w | 22/168 (13.10) | 1.42 (0.86, 2.34) | 0.17 | 1.61 (0.93, 2.78) | 0.09 | 1.95 (1.10, 3.45) | 0.023 |
| Post-3w | 22/180 (12.22) | 1.44 (0.87, 2.39) | 0.15 | 1.93 (1.12, 3.32) | 0.018 | 2.25 (1.27, 3.98) | 0.006 |
| Post-4w or more | 26/221 (11.76) | 1.24 (0.77, 1.97) | 0.38 | 1.34 (0.81, 2.23) | 0.25 | 1.24 (0.72, 2.14) | 0.44 |
Model 1: Adjusted for age (continuous) and sex (men or women).
Model 2: Additionally adjusted for BMI (continuous), smoking (yes or no), COVID-19 vaccination status (yes or no), number of comorbidities (0, 1, 2, 3, ≥4) and history of cancer (yes or no).
Model 3: Further adjusted for ASA classification (grades 1–2 or grades 3–5), grade of surgery (minor or major), urgency of surgery (elective or emergency), duration of surgery (≤240 min or >240 min), general anaesthesia (yes or no) and type of surgery (thoracic, head and neck, cardiovascular, digestive, breast, gynaecological and obstetrics, orthopaedic and other surgeries).
Pre-1w, preoperative COVID-19 within 1 week; Pre-2w, preoperative COVID-19 within 1–2 weeks; Pre-3w, preoperative COVID-19 within 2–3 weeks; Pre-4w or more, preoperative COVID-19 beyond 3 weeks.
Post-1w, postoperative COVID-19 within 1e week; Post-2w, postoperative COVID-19 within 1–2 weeks; Post-3w, postoperative COVID-19 within 2–3 weeks; Post-4w or more, postoperative COVID-19 beyond 3 weeks.
ASA, American Society of Anesthesiologists; BMI, body mass index.