Over the past decade, longstanding concern about excess hospital capacity has given way to new concerns about hospital overcrowding and ambulance diversion. Although many hospitals closed or downsized during this period, the potential for more closures continues to loom across the United States. While competitive markets may force low-quality hospitals to exit the market, hospital survival may also be driven by factors unrelated to quality of care such as payer mix and access to public funding to prevent closure. It is, therefore, unknown whether the exit and survival behavior of hospitals increases or reduces healthcare quality. The proposed study seeks to fill this gap in knowledge by pursuing the following aims: 1) determine whether the quality of care at closing hospitals is higher or lower than the quality of care at hospitals that remain open, and 2) determine whether patients in market areas with a recent hospital closure experience improvement or deterioration in the quality of hospital care. The study is based on HCUP-SID and other discharge data for nine states from 1998 to 2003. Logistic regression models will be used to determine whether patients of hospitals that later closed received lower quality of care (after risk adjustment) than patients of hospitals that remained open during the study period. Quality measures are based on Inpatient Quality Indicators (IQI's) and Patient Safety Indicators (PSI's). Similar models will determine whether quality indicators improved or deteriorated in markets that experienced a hospital closure relative to markets where no closures occurred. Hospital closure has become a high-profile issue in New York and New Jersey where formal commissions have been created to make recommendations about potential closures. Interest in this issue is becoming prominent in other states as well, since the problem of hospital closure is national in scope. Findings from the proposed study will have direct relevance for public officials with oversight responsibility for hospital capacity and access. In addition, the study will provide a foundation for future work on how changes in local healthcare infrastructure affect the health of local communities. Future work will include predictors of quality changes in markets that experience a hospital closure, the mechanisms by which these changes can affect quality, and how these changes affect pre-existing disparities in healthcare quality and access for vulnerable populations. ? ? ? ?