The impact of healthcare-associated methicillin-resistant Staphylococcus aureus infections on post-discharge healthcare costs and utilization
A number of studies have estimated the cost associated with healthcare-associated methicillin resistant Staphylococcus aureus (MRSA) infections (MRSA HAIs) during the primary hospitalization. However, little is known about their impact on post-discharge resource utilization. The purpose of this study was to estimate healthcare costs and utilization attributable to MRSA HAIs after discharge from the hospital.
Our study cohort consisted of patients with an inpatient admission lasting longer than 48 hours within the US Department of Veterans Affairs (VA) system between October 1, 2007 and November 30, 2010. Of these patients, we identified those with an MRSA HAI from microbiology reports in the VA electronic medical record. MRSA HAIs were defined as positive clinical cultures for MRSA between 48 hours after admission and 48 hours after discharge. We constructed multivariable regression models to assess the impact of MRSA HAIs on post-discharge outpatient, inpatient, and pharmacy costs and utilization in the 365 days following discharge. We used propensity score matching to identify a subset of patients without MRSA HAI who were similar in observable characteristics to those with MRSA HAI.
After applying our inclusion criteria, our cohort included 369,743 inpatients, of whom, 3,599 (1.0%) had MRSA HAIs. Our final analysis sample included 3,592 patients with MRSA HAI who had been matched to 3,592 patients without MRSA HAI. Using generalized linear models, we found that MRSA HAIs resulted in greater pharmacy ($710, p<0.0001) and inpatient costs ($11,044, p<0.0001) during the 365-day post-discharge period. In addition, using logistic and negative binomial regressions, we found that having an MRSA HAI increased the risk of a readmission (OR=1.396, p<0.0001), the number of prescriptions (IRR=1.138, p<0.0001), and inpatient days (IRR=1.204, p<0.0001) but decreased the number of subsequent outpatient encounters (IRR=0.941, p=0.008).
This study shows that MRSA HAIs are associated with significant post-discharge health care cost and utilization. These findings suggest that financial benefits resulting from infection prevention efforts may extend beyond the initial hospital stay.
R. E. Nelson,
C. F. Liu, None
M. Samore, None
M. Evans, None
N. Graves, None
B. Lee, None
M. Rubin, None