Cover: Surgical Site Infections Following Ambulatory Surgery Procedures

Surgical Site Infections Following Ambulatory Surgery Procedures

Published in: JAMA The Journal of the American Medical Association, v. 311, no. 7, Feb. 2014, p. 709-716

Posted on Feb 1, 2014

by Pamela L. Owens, Marguerite L. Barrett, Susan O. Raetzman, Melinda Maggard Gibbons, Claudia A. Steiner

Research Question

  1. How serious, and how frequent, are surgical site infections among patients undergoing outpatient surgery?

IMPORTANCE: Surgical site infections can result in substantial morbidity following inpatient surgery. Little is known about serious infections following ambulatory surgery. OBJECTIVE: To determine the incidence of clinically significant surgical site infections (CS-SSIs) following low- to moderate-risk ambulatory surgery in patients with low risk for surgical complications. DESIGN, SETTING, AND PARTICIPANTS: Retrospective analysis of ambulatory surgical procedures complicated by CS-SSIs that require a postsurgical acute care visit (defined as subsequent hospitalization or ambulatory surgical visit for infection) using the 2010 Healthcare Cost and Utilization Project State Ambulatory Surgery and State Inpatient Databases for 8 geographically dispersed states (California, Florida, Georgia, Hawaii, Missouri, Nebraska, New York, and Tennessee) representing one-third of the US population. Index cases included 284 098 ambulatory surgical procedures (general surgery, orthopedic, neurosurgical, gynecologic, and urologic) in adult patients with low surgical risk (defined as not seen in past 30 days in acute care, length of stay less than 2 days, no other surgery on the same day, and discharged home and no infection coded on the same day). MAIN OUTCOMES AND MEASURES: Rates of 14- and 30-day postsurgical acute care visits for CS-SSIs following ambulatory surgery. RESULTS: Postsurgical acute care visits for CS-SSIs occurred in 3.09 (95% CI, 2.89-3.30) per 1000 ambulatory surgical procedures at 14 days and 4.84 (95% CI, 4.59-5.10) per 1000 at 30 days. Two-thirds (63.7%) of all visits for CS-SSI occurred within 14 days of the surgery; of those visits, 93.2% (95% CI, 91.3%-94.7%) involved treatment in the inpatient setting. All-cause inpatient or outpatient postsurgical visits, including those for CS-SSIs, following ambulatory surgery occurred in 19.99 (95% CI, 19.48-20.51) per 1000 ambulatory surgical procedures at 14 days and 33.62 (95% CI, 32.96-34.29) per 1000 at 30 days. CONCLUSIONS AND RELEVANCE: Among patients in 8 states undergoing ambulatory surgery, rates of postsurgical visits for CS-SSIs were low relative to all causes; however, they may represent a substantial number of adverse outcomes in aggregate. Thus, these serious infections merit quality improvement efforts to minimize their occurrence.

Key Findings

  • Relative to all causes of infections among patients undergoing outpatient surgery, rates of surgical site infections are low.
  • However, as outpatient surgery is common, they represent a substantial number of adverse outcomes in aggregate, and some of these infections are serious.
  • Two-thirds of surgical site infections occurred within two weeks of the surgery.


  • Quality improvement efforts are merited to reduce infectious complications. Likewise, attention to their early detection may prove beneficial in lessening the severity.

This report is part of the RAND external publication series. Many RAND studies are published in peer-reviewed scholarly journals, as chapters in commercial books, or as documents published by other organizations.

RAND is a nonprofit institution that helps improve policy and decisionmaking through research and analysis. RAND's publications do not necessarily reflect the opinions of its research clients and sponsors.