1176. Comparing billing vs. National Healthcare Safety Network surveillance rates of hospital-acquired infections
Session: Poster Abstract Session: Surveillance HAIs: Advancing the Science
Friday, October 19, 2012
Room: SDCC Poster Hall F-H
  • Tse ID Week Comparing Billing vs. National Healthcare Safety Network (NHSN) Rates.pdf (111.5 kB)
  • Background: In October 2008, the Centers for Medicare and Medicaid Services (CMS) implemented a policy of non-payment for hospital-acquired conditions (HAC) that were not present on admission.  In particular, ICD9 codes for catheter related bloodstream infections (CRBSI) and catheter-associated urinary tract infections (CAUTI) were targeted for non-payment.  In addition, there has been consideration of adding ventilator-associated pneumonia (VAP) the HAC list.  We sought to compare billing rates of infection with corresponding NHSN infection rates in a sample of 22 California (CA) and 45 New York (NY) hospitals.

    Methods: Rates of CLABSI were obtained for 22 CA and 45 NY hospitals that reported on this outcome to the National Healthcare Safety Network (NHSN) in 2009. NHSN rates of CAUTI and VAP were also obtained for a subset of the CA (N=17 for CAUTI; N=18 for VAP) and NY (N=40 for CAUTI; N=38 for VAP) hospitals that reported on each of these outcomes in 2009. Billing infection rates were evaluated for the same hospitals based on ICD9 codes from the CA and NY State Inpatient Databases (SID).  To compare billing data to NHSN data, both rates were expressed as the number of infections per 1,000 patient days and rate ratios and 95% CIs were estimated for CLABSI/CRBSI, CAUTI and VAP.

    Results: CRBSI rates measured by ICD9 codes in SID were significantly lower than CLABSI rates reported to NHSN (Rate ratio = 0.23, 95% CI 0.20, 0.25).  Similarly, rates of CAUTI (Rate ratio = 0.12, 95% CI 0.10, 0.14) and VAP (Rate ratio = 0.16, 95% CI 0.13, 0.19) were significantly lower using billing data vs. NHSN data.

    Conclusion: Billing data are poorly sensitive for identifying “true” infection rates in hospitals.  The impact of the CMS policy may be mitigated by the poor sensitivity of the metric chosen by CMS for non-payment.

    Alison Tse, ScD1, Robert Jin, MS1, Charlene Gay, BA1, Michael S. Calderwood, MD, MPH1,2 and Grace Lee, Pharm.D1,3, (1)Department of Population Medicine, Harvard Pilgrim Health Care Institute and Harvard Medical School, Boston, MA, (2)Infectious Diseases, Brigham and Women's Hospital, Boston, MA, (3)Division of Infectious Diseases, Children's Hospital Boston, Boston, MA


    A. Tse, None

    R. Jin, None

    C. Gay, None

    M. S. Calderwood, None

    G. Lee, None

    Findings in the abstracts are embargoed until 12:01 a.m. PST, Oct. 17th with the exception of research findings presented at the IDWeek press conferences.