Epidemiology of surgical-site infections diagnosed after hospital discharge: A prospective cohort study

OBJECTIVE: To study postoperative infections in hospital and after discharg e, and to identify the risk factors for such infections. DESIGN: Prospective cohort study, with telephone followup for 1 month after hospital discharge. SETTING: The general surgery service of a tertiary hospital in Spain. MAIN OUTCOME MEASURE: In-hospital and postdischarge surgical-site infection (SSI), always confirmed by a physician. RESULTS: Of the 1,506 patients initially enrolled, 29 died during hospital stay, and 33 were lost to postdischarge follow-up. An SSI was identified pr ior to discharge in 123 patients and after discharge in 103. For several va riables (age, serum albumin, glycemia, lengths of preoperative and postoper ative hospital stay, etc), there were no differences between patients with postdischarge SSI and noninfected patients; however, there were differences detected between patients with postdischarge SSI and in-hospital SSI, as w ell as between patients with in-hospital SSI and noninfected patients. The analysis of risk factors showed that most predictors for in-hospital SSI di d not behave in the same manner for postdischarge SSI. Stepwise logistic re gression only identified chemoprophylaxis, age (advanced age was a preventi ve factor), and body mass index as independent risk factors for postdischar ge SSI. Differences in risk factors between in-hospital and postdischarge S SIs remained even after controlling for time from operation to diagnosis. CONCLUSIONS: Most predictors of in-hospital SSI were not predictors of post discharge SSI (Infect Control Hosp Epidemiol 2001;22:24-30).