Measuring equitable care in multi-hospital markets: A Proportional Share Index Application in New York City.

Community members, elected officials, and policy makers are increasingly calling attention to the issue of inequities in hospital utilization and resource allocation within consolidated multi-hospital markets in the United States. Innovative policy solutions are required to re-shape the incentives driving hospital business practices and behaviors that produce inequitable outcomes and to ensure that equity, as well as economics, drives these business decisions. New measures can drive evidence-informed policy making and track the impact of new laws, regulations, and practices. In this paper, we illustrate the development and potential applications of the Proportional Share Index (PSI) using New York City (NYC) as a case study, highlighting its ability to quantify and track equitable access to hospitals across multi-hospital markets. The PSI incorporates both a measure of those who are covered by Medicaid or who are self-pay (largely uninsured) and hospital capacity in determining whether a given hospital is providing its proportionate, fair amount of care to these populations. We discuss how the PSI and related measures may inform policy interventions aimed at mitigating health inequities.