That means physicians are often unaware of information that patients assume they know: test results, diagnoses, medications, and more. When the Pew Charitable Trusts recruited consumers to participate in focus groups about patient matching, most were unaware that the problem even exists. But they quickly grasped how dangerous the situation can be, says Ben Moscovitch, Pew’s project director for health information technology.

“The patients that we spoke to in our focus groups indicated that they wanted this problem solved,” he says.

On its face, patient matching seems like a simple problem to fix, until you look closely.

One root problem is that the health-care industry has been consolidating for years, and the pace of mergers is only speeding up. Take the example of Northwell Health. Already the largest health-care provider in New York State, Northwell is growing rapidly through acquisitions. Every time the system adds a new hospital, its medical records are integrated—and duplicates proliferate. Is the Raj Patel treated at the newly acquired hospital the same Raj Patel already on file at Northwell?

Meanwhile, Northwell’s 23 hospitals and more than 700 clinics are creating new duplicate records every day. Anywhere from 70,000 to 100,000 people seek care at one of its facilities each month, and busy registrars often scramble to keep up. “When you get a very common name like Smith, Gonzalez, Rodriguez, Miller, you’ll call that patient up in the system and you’ll literally get 50 of them,” says Frank Danza, the senior vice president for revenue-cycle management at the health system. “Rather than try to figure out which of those 50 is the right one, [the registrar] will create a new case, knowing that there’s a way to reconcile it later on.”

He’s not exaggerating. In 2016, Harris Health System in Houston reported that it had 2,488 records with the name Maria Garcia; of those, 231 shared the same birth date, suggesting that some of them refer to the same individual. But if those records have different addresses or telephone numbers, who can be sure? Harris also found nearly 250,000 cases in which two or more patients have the same first and last name; more than 76,000 times in which five or more patients share a first and last name; and nearly 70,000 instances of two or more patients sharing a first name, last name, and date of birth.

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In that head-spinning milieu, the College of Health Care Information Management Executives, the professional organization for chief information officers in the health-care industry, launched the National Patient ID Challenge in 2015, offering a $1 million prize to anyone who could develop a software tool that could match patient records with 100 percent accuracy. More than 350 individuals and teams registered to compete; more than two years later, the challenge was abandoned without a winner.