Differences in the rates of patient safety events by payer: implications for providers and policymakers.

BACKGROUND: The reduction of adverse patient safety events and the equitable treatment of patients in hospitals are clinical and policy priorities. Health services researchers have identified disparities in the quality of care provided to patients, both by demographic characteristics and insurance status. However, less is known about the extent to which disparities reflect differences in the places where patients obtain care, versus disparities in the quality of care provided to different groups of patients in the same hospital.
OBJECTIVE: In this study, we examine whether the rate of adverse patient safety events differs by the insurance status of patients within the same hospital.
METHODS: Using discharge data from hospitals in 11 states, we compared risk-adjusted rates for 13 AHRQ Patient Safety Indicators by Medicare, Medicaid, and Private payer insurance status, within the same hospitals. We used multivariate regression to assess the relationship between insurance status and rates of adverse patient safety events within hospitals.
RESULTS: Medicare and Medicaid patients experienced significantly more adverse safety events than private pay patients for 12 and 7 Patient Safety Indicators, respectively (at P < 0.05 or better). However, Medicaid patients had significantly lower event rates than private payers on 2 Patient Safety Indicators.
CONCLUSIONS: Risk-adjusted Patient Safety Indicator rates varied with patients' insurance within the same hospital. More research is needed to determine the cause of differences in care quality received by patients at the same hospital, especially if quality measures are to be used for payment.