Infect. Control Hosp. Epidemiol., December 2006, Vol. 27, No. 12, p.1324-1329.
objective. To evaluate the impact of postdischarge surveillance on surgical site infection (SSI) rates after orthopedic surgery.

setting. Nine hospitals participating in the Finnish Hospital Infection mProgram.

patients. All patients who underwent hip or knee arthroplasty or open reduction of a femur fracture during 1999-2002.

results. The date of discharge was available for 11,812 procedures (90%). The median length of hospital stay was 8 days (range per hospital, 6-9 days). The overall SSI rate was 3.3% (range, 0.8%-6.4%). Of 384 SSIs detected, 216 (56%; range, 28%-90%) were detected after discharge: 93 (43%) were detected on readmission to the hospital, 73 (34%) at completion of a postdischarge questionnaire, and 23(11%) at a follow-up visit. For 27 postdischarge SSIs (13%), the location of detection was unknown. Altogether, 32 (86%) of 37 of organ/space SSIs, 57 (80%) of 71 deep incisional SSIs, and 127 (46%) of 276 superficial incisional SSIs were detected after discharge. Most SSIs(70%) detected on readmission were severe (organ/space or deep incisional), whereas most SSIs (86%) detected at follow-up visits or at
completion of a postdischarge questionnaire were superficial. Of all SSIs, 78% (range, 48%-100%) were microbiologically confirmed. Microbiologic confirmation was less common after discharge than during postoperative hospital stay (66% vs 93%; P ! .001).

conclusions. Postdischarge surveillance had a large impact on the rate of SSI detected after orthopedic surgery. However, postdischarge
surveillance conducted by means of a questionnaire detected only a minority of deep incisional and organ/space SSIs.
Kaisa Huotari, MD; Outi Lyytikäinen, MD, PhD;