Incidence and impact of surgical site infections on length of stay and cost of care for patients undergoing open procedures.

Background: Surgical site infections (SSIs) are associated with increased morbidity and mortality; however, current SSI rates across open procedures and their effect on healthcare delivery are unknown. The objective of this study was to examine incidence of SSIs for open surgical procedures in the United States and impact on length of stay (LOS) and costs

Methods: This retrospective study utilizing 2019-2020 data from Medicare and Premier identified patients with SSIs occurring during hospitalization or within 90 days of discharge. Propensity score matching was used to calculate incremental LOS and costs attributable to SSIs. Mean LOS and costs attributable to SSIs for the index admission, readmissions, and outpatient visits were summed by procedure and Charlson Comorbidity Index score to estimate the overall impact of an SSI on LOS and costs across healthcare settings.

Results: SSI rates were 2.0% for 2,696,986 Medicare and 1.8% for 1,846,254 Premier open surgeries. Total incremental LOS and cost per SSI, including index admission, readmissions, and outpatient visits were 9.3 days and $18,626 for Medicare patients and 7.8 days and $20,979 for Premier patients. SSI rates were higher for urgent/emergency surgeries compared to overall SSI rates. Although less common that superficial SSIs, deep SSIs resulted in higher incremental LOS and index costs for the index admission and for SSI-related readmissions.

Conclusions: This study of SSIs utilizing two large national databases provides robust data and analytics reinforcing and bolstering current evidence that SSIs occur infrequently but are detrimental to patients in terms of increased LOS and care costs.