Electronic health records are widely seen as a way to improve patient care, reduce duplication of services, and potentially cut costs in the U.S. health care system.

But they also raise fresh privacy concerns, with hundreds or thousands of employees having potential immediate access to a patient’s sensitive medical information.

A possible information breach at Miami Valley Hospital is one of the latest local reminders of those privacy concerns. It involves Brennan Eden, a “high-profile” patient whose sensational Aug. 23 vehicle crash on Interstate 675 was captured on video viewed nationwide.

About 200 hospital employees accessed Eden’s medical records, but it’s not yet clear whether any of that access was due to curiosity. Under federal law, workers may only access a patient’s electronic medical records for a legitimate business need...