The quality of care delivered to patients within the same hospital varies by insurance type.

In attempting to explain why hospitals vary in the quality of care delivered to patients, a considerable body of health policy research points to differences in hospital characteristics such as ownership, safety-net status, and geographic location as the most important contributing factors. This article examines the extent to which a patient's type or lack of insurance may also play a role in determining the quality of care received at any given hospital. We compared within-hospital quality, as measured by risk-adjusted mortality rates, for patients according to their insurance status. We examined the Agency for Healthcare Research and Quality's innovative Inpatient Quality Indicators and pooled 2006-08 State Inpatient Database records from eleven states. We found that privately insured patients had lower risk-adjusted mortality rates than did Medicare enrollees for twelve out of fifteen quality measures examined. To a lesser extent, privately insured patients also had lower risk-adjusted mortality rates than those in other payer groups. Medicare patients appeared particularly vulnerable to receiving inferior care. These findings suggest that to help reduce care disparities, public payers and hospitals should measure care quality for different insurance groups and monitor differences in treatment practices within hospitals.