Patients in California may find a shuttered glass door the next time they seek out emergency care, as hospitals across the state close emergency rooms. California hospitals that serve large numbers of blacks and Medicaid patients, who often rely on ERs the most, run a higher risk of closing the emergency deparment, according to an analysis just published in the Annals of Emergency Medicine. Using data from 1998 to 2008 ? a period when 7% of the Golden State's emergency departments closed ? researchers found that for every 10% increase in black patients, a hospital's risk of shutting down its ER shot up by 40%.