Electronically Available Comorbidities Should Be Used in Surgical Site Infection Risk Adjustment. Clin Infect Dis 2017 Sep 01;65(5):803-810
Date
05/10/2017Pubmed ID
28481976Pubmed Central ID
PMC5850642DOI
10.1093/cid/cix431Scopus ID
2-s2.0-85028621891 (requires institutional sign-in at Scopus site) 16 CitationsAbstract
BACKGROUND: Healthcare-associated infections such as surgical site infections (SSIs) are used by the Centers for Medicare and Medicaid Services (CMS) as pay-for-performance metrics. Risk adjustment allows a fairer comparison of SSI rates across hospitals. Until 2016, Centers for Disease Control and Prevention (CDC) risk adjustment models for pay-for-performance SSI did not adjust for patient comorbidities. New 2016 CDC models only adjust for body mass index and diabetes.
METHODS: We performed a multicenter retrospective cohort study of patients undergoing surgical procedures at 28 US hospitals. Demographic data and International Classification of Diseases, Ninth Revision codes were obtained on patients undergoing colectomy, hysterectomy, and knee and hip replacement procedures. Complex SSIs were identified by infection preventionists at each hospital using CDC criteria. Model performance was evaluated using measures of discrimination and calibration. Hospitals were ranked by SSI proportion and risk-adjusted standardized infection ratios (SIR) to assess the impact of comorbidity adjustment on public reporting.
RESULTS: Of 45394 patients at 28 hospitals, 573 (1.3%) developed a complex SSI. A model containing procedure type, age, race, smoking, diabetes, liver disease, obesity, renal failure, and malnutrition showed good discrimination (C-statistic, 0.73) and calibration. When comparing hospital rankings by crude proportion to risk-adjusted ranks, 24 of 28 (86%) hospitals changed ranks, 16 (57%) changed by ≥2 ranks, and 4 (14%) changed by >10 ranks.
CONCLUSIONS: We developed a well-performing risk adjustment model for SSI using electronically available comorbidities. Comorbidity-based risk adjustment should be strongly considered by the CDC and CMS to adequately compare SSI rates across hospitals.
Author List
Jackson SS, Leekha S, Magder LS, Pineles L, Anderson DJ, Trick WE, Woeltje KF, Kaye KS, Lowe TJ, Harris ADAuthor
Keith F. Woeltje MD, PhD Associate Dean, Professor in the Medicine department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AdultAged
Comorbidity
Female
Humans
Male
Middle Aged
Retrospective Studies
Risk Adjustment
Risk Factors
Surgical Wound Infection
United States
