Proportion of Surgical Site Infections Occurring after Hospital Discharge: A Systematic Review

Background: Surgical site infection (SSI) is the most common type of healthcare-associated infection, contributing to substantial annual morbidity, costs, and deaths. In the United States it is the number one reason for hospital re-admission after surgery. Relatively little attention has been paid to the proportion of SSIs that occur after discharge. This paper systematically reviews two decades of publications to characterize better the proportion of SSIs that are identified after discharge and the need for better early detection and treatment. Methods: A restricted systematic literature search was conducted in PubMed to identify English-language studies published after 1995 that include the occurrence of pre-discharge and post-discharge SSIs. The data abstracted were the date of publication, country of origin, procedure, study design, surveillance system, population size, follow-up rate, and SSI counts and proportions. Descriptive statistics and forest plots were used to characterize the data set, represent the overall proportion of SSIs occurring after discharge, and assess the heterogeneity of the studies. Results: A total of 55 articles met the inclusion criteria, with data from 1,432,293 operations and 141,347 SSIs based on studies from 15 countries. The overall proportion of operations leading to SSI was 9.9%. Of the 141,347 infections, 84,984 (60.1%) appeared after discharge. The proportion of SSIs after discharge differed among studies, from 13.5 to 94.8, and was heterogeneous for all studies and for most individual surgery types. Conclusion: Post-discharge SSIs constitute the majority of these infections and pose a substantial disease burden for surgical patients globally and for different surgery types. Further examination is warranted to determine the methodologic and clinical factors moderating the proportion of post-discharge SSIs.