The effect of surgical wound infection on postoperative hospital stay

Abstract

Objective: To determine the effect of surgical wound infection on postoperative duration of hospital stay.

Design: A case-control study nested within a cohort.

Setting: A tertiary-care hospital.

Patients: Selected from a cohort of 4702 inpatients who underwent surgical procedures over a 12-month period. There were 3602 patients, 1100 having been excluded because of lack of infection associated with a particular surgical procedure, because of "lumping" of procedures under a nonhomogeneous heading or because a procedure was unlikely to be the reason for the patient's hospitalization.

Main outcome measure: Postoperative duration of hospital stay.

Results: In the cohort 89 wound infections were identified, 73 of these occurring with procedures selected for study. Five patients were excluded from the study because of data deficiencies, leaving 68 patients who underwent 15 different procedures. These were compared with 136 control patients selected by stratified random sample from a list of patients who underwent the same risk-indexed procedure in the same surgical division. Wound infection patients and controls did not differ in anesthetic risk score or procedure duration. Patients with infection remained in hospital 19.5 days longer than controls (95% confidence interval, range from 11.0 to 27.9 days). Deep-seated infections prolonged the hospital stay more than superficial incisional infections (24.3 versus 13.2 days).

Conclusions: Surgical wound infection markedly prolonged the duration of hospitalization in the University of Alberta Hospitals, longer than that documented in previous studies in other countries. Maximizing opportunities to prevent wound infection would be beneficial to both patients and hospitals.