1229. Examining the Impact of Medicare’s Policy of Non-Payment for Preventable Complications on Rates of Mediastinitis following Coronary Artery Bypass Graft Surgery in U.S. Hospitals
Session: Oral Abstract Session: Impact of National Policy on HAI Reporting and Prevention
Friday, October 19, 2012: 2:30 PM
Room: SDCC 32 AB
Background: In October 2008, the Centers for Medicare and Medicaid Services (CMS) stopped providing additional payment to hospitals for certain “preventable” complications that were not present on admission. This included mediastinitis (ICD-9 519.2) following coronary artery bypass graft surgery (CABG). The goal of this policy was to encourage hospitals to focus on SSI reduction. We studied the impact of this policy.

Methods: We conducted an interrupted time series analysis comparing hospital infection rates from 1/1/07-9/30/08 vs. 10/1/08-12/31/10. SSI rates were obtained from the National Healthcare Safety Network (NHSN) for 152 hospitals that agreed to participate across 29 states. We used logistic regression mixed effects models to evaluate the impact of the CMS policy, adjusting for secular trends and NHSN risk class. We also evaluated the policy impact on billing rates to assess changes in coding in the pre- and post-intervention periods. For this analysis, we used CMS claims data from the 1,219 U.S. hospitals performing CABG from 1/1/07-12/31/09.

Results: The hospitals in our study reported 102,325 CABG procedures to NHSN from 1/1/07-12/31/10. There was no significant change in the secular trend in mediastinitis rates in the post vs. pre-intervention periods (Ratio of slopes = 0.80 [95% confidence interval 0.52-1.22]). Similarly, we found no impact of the CMS policy on the broader category of sternal deep and organ/space SSIs (Ratio of slopes = 0.98 [95% confidence interval 0.78-1.23]). The CMS claims included 404,592 CABG procedures from 1/1/07-12/31/09. There was an increasing trend in billing for mediastinitis in the pre-intervention period and a decreasing trend in the post-intervention period, with a significant difference (Ratio of slopes = 0.14 [95% confidence interval 0.04-0.50]).

Conclusion: We did not find an impact of the CMS non-payment for preventable complications policy on reducing NHSN rates of mediastinitis (or the broader category of sternal deep and organ/space SSIs) in U.S. hospitals. However, there does appear to be a significant change in billing rates of mediastinitis following the implementation of the non-payment policy, which may reflect changes in billing practices rather than improvements in patient outcomes.

Michael S. Calderwood, MD, MPH, Ken Kleinman, ScD, Alison Tse, ScD, Robert Jin, MS, Richard Platt, MD, MS, FSHEA and Grace M. Lee, MD, MPH, Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, MA


M. S. Calderwood, None

K. Kleinman, None

A. Tse, None

R. Jin, None

R. Platt, None

G. M. Lee, None

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