Are Rates of Methicillin-Resistant Staphylococcus aureus and Clostridioides difficile Associated With Quality and Clinical Outcomes in US Acute Care Hospitals?

The purpose of this study was to examine the association between rates of methicillin-resistant Staphylococcus aureus (MRSA)/Clostridioides difficile and quality and clinical outcomes in US acute care hospitals. The population was all Medicare-certified US acute care hospitals with MRSA/C difficile standardized infection ratio (SIR) data available from 2013 to 2017. Hospital-level data from the Centers for Medicare & Medicaid Services were used to estimate hospital and time fixed effects models for 30-day hospital readmissions, length of stay, 30-day mortality, and days in the intensive care unit. The key explanatory variables were SIR for MRSA and C difficile. No association was found between MRSA or C difficile rates and any of the 4 outcomes. The null results add to the mixed evidence in the field, but there are likely residual confounding factors. Future research should use larger samples of patient-level data and appropriate methods to provide evidence to guide efforts to tackle antimicrobial resistance.