Impact of Medicare's payment policy on mediastinitis following coronary artery bypass graft surgery in US hospitals.

View Abstract

BACKGROUND

The Centers for Medicare and Medicaid Services (CMS) implemented a policy in October 2008 to eliminate additional Medicare payment for mediastinitis following coronary artery bypass graft (CABG) surgery.

OBJECTIVE

To evaluate the impact of this policy on mediastinitis rates, using Medicare claims and National Healthcare Safety Network (NHSN) prospective surveillance data.

METHODS

We used an interrupted time series design to compare mediastinitis rates before and after the policy, adjusted for secular trends. Billing rates came from Medicare inpatient claims following 638,761 CABG procedures in 1,234 US hospitals (January 2006-September 2010). Prospective surveillance rates came from 151 NHSN hospitals in 29 states performing 94,739 CABG procedures (January 2007-September 2010). Logistic regression mixed-effects models estimated trends for mediastinitis rates.

RESULTS

We found a sudden drop in coding for index admission mediastinitis at the time of policy implementation (odds ratio, 0.36 [95% confidence interval (CI), 0.23-0.57]) and a decreasing trend in coding for index admission mediastinitis in the postintervention period compared with the preintervention period (ratio of slopes, 0.83 [95% CI, 0.74-0.95]). However, we saw no impact of the policy on infection rates as measured using NHSN data. Our results were not affected by changes in patient risk over time, heterogeneity in hospital demographics, or timing of hospital participation in NHSN.

CONCLUSIONS

The CMS policy of withholding additional Medicare payment for mediastinitis on the basis of claims-based evidence of infection was associated with changes in coding for infections but not with changes in actual infection rates during the first 2 years after policy implementation.

Abbreviation
Infect Control Hosp Epidemiol
Publication Date
2013-12-24
Volume
35
Issue
2
Page Numbers
144-51
Pubmed ID
24442076
Medium
Print-Electronic
Full Title
Impact of Medicare's payment policy on mediastinitis following coronary artery bypass graft surgery in US hospitals.
Authors
Calderwood MS, Kleinman K, Soumerai SB, Jin R, Gay C, Platt R, Kassler W, Goldmann DA, Jha AK, Lee GM