Surgical site infections during the COVID-19 era: A retrospective, multicenter analysis

•Multicenter analysis evaluating perioperative COVID-19 precautions impact on SSIs.•Perioperative COVID-19 precautions did not significantly reduce the risk of SSIs.•Further study is needed to evaluate modifiable environmental factors effect on SSIs. Surgical site infections (SSIs) are an undesired perioperative outcome. Recent studies have shown increases in hospital acquired infections during the coronavirus disease 2019 (COVID-19) pandemic. The objective of this study was to evaluate postoperative SSIs in the COVID-19-era compared to a historical cohort at a large, multicenter, academic institution. A retrospective review of all patients who underwent National Health and Safety Network (NHSN) inpatient surgical procedures between January 1, 2018 and December 31, 2020. Patients from the COVID-19-era (March-December 2020) were compared and matched 1:1 with historical controls (2018/2019) utilizing the standardized infection ratio (SIR) to detect difference. During the study period, 29,904 patients underwent NHSN procedures at our institution. When patients from the matched cohort (2018/2019) were compared to the COVID-19-era cohort (2020), a decreased risk of SSI was observed following colorectal surgery (RR = 0.94, 95% CI [0.65, 1.37], P = .76), hysterectomy (RR = 0.88, 95% CI [0.39, 1.99], P = .75), and knee prothesis surgery (RR = 0.95, 95% CI [0.52, 1.74], P = .88), though not statistically significant. An increased risk of SSI was observed following hip prosthesis surgery (RR 1.09, 95% CI [0.68, 1.75], P = .72), though not statistically significant. The risk of SSI in patients who underwent NHSN inpatient surgical procedures in 2020 with perioperative COVID-19 precautions was not significantly different when compared to matched controls at our large, multicenter, academic institution.