Fig. 1.

Adjusted odds ratios for mortality and pulmonary complications within 30 days after surgery

a Mortality and b pulmonary complications. Group 1, positive reverse transcriptase (RT)–PCR test within 5 days before surgery; group 2, positive RT–PCR test within 5 days after surgery; group 3, positive RT–PCR test between 5 and 30 days after surgery; group 4, positive RT–PCR at least 5 days before surgery; and group 5, negative RT–PCR test(s) or positive RT–PCR test more than 30 days after surgery.