Author's reply - factors affecting the mortality of patients with COVID-19 undergoing surgery and the safety of medical staff: A systematic review and meta-analysis.

We thank Lawday et al. for their comments on our paper [1]. We concur with Lawday and colleagues that cohort studies should have been included in our meta-analysis in order to provide more comprehensive information. In the 47 studies included, 42 were case reports/series, and data from these case reports/series were directly combined and analyzed to obtain the conclusion that the perioperative mortality of patients with COVID-19 undergoing surgery was 6% [1]. While ideally/theoretically, cohort studies should be included in this meta-analysis, direct combining data of different literature types may affect the reliability of meta-analysis results. In the studies mentioned by Lawday et al., the 30-day mortality rates vary between 16%~23.8% in COVID-19 patients with severe acute respiratory syndrome undergoing surgeries [2,3]. In our meta-analysis, we only focused on analyzing the perioperative mortality based on the data availability from the studies included, and should extend the follow-up time when possible, as 30 days-mortality can reflect the long-term effect of COVID-19 on surgery outcome. In our meta-analysis, about 65 cases cesarian were in the I-II level of surgical difficulty category, which was associated with lower mortality 0.3–1.4% [4]. This should have decreased the overall perioperative mortality. In addition, patients’ ASA physical status is associated with postoperative mortality at 48 h, and overall mortality at 48 h among patients undergoing emergent and elective procedures are respectively 1.27% and 0.03% in a large contemporary cohort [5]. Thus, the 6% perioperative mortality as we reported should urge surgeons to proceed with caution.

Declaration of Competing Interest

None.