Data sharing may be essential to hospital strategies to identify high users and improve community health, according to a study published online by JAMA Internal Medicine. The study examined patterns of hospital use by patients with more than five emergency department visits to Maryland hospitals in calendar year 2014, and the share of hospital admissions received by the most used hospital in each zip code. It found that nearly 70% of frequent ED users visited more than one hospital, and that 53% of the state’s residents lived in zip codes where no single hospital received more than half of inpatient volume. “As a result of new payment initiatives that favor reductions in avoidable illnesses, more hospitals are working to identify and assist high utilizers,” the authors notes. “For more than two-thirds of frequent visitors to emergency departments in Maryland, however, no single hospital had a full picture of their care.” The study does not account for the fact that some hospitals in the same system may be able to share data, the authors note.