Data Set Too Small to Support Claim of 250,000 Annual ER Deaths Due to Misdiagnosis

(p. A17) A shocking headline recently claimed that every year 250,000 people in the U.S. die after misdiagnosis in the emergency room. Even more shocking, the statistic was extrapolated from the death of one man—in a Canadian emergency room more than a decade ago.

. . .

The statistical methods used to arrive at the report’s estimate of 250,000 deaths are very bad, resulting in inaccurate findings that exaggerate potential harm in ERs. The estimate was derived from a single study that included only 503 patients discharged from two Canadian emergency rooms from August to December 2004. Researchers found that among the 503 patients, one person unexpectedly died related to a delay in diagnosis by an ER physician. The patient had signs of an aortic dissection—a tear in the major vessel that carries blood from the heart. For reasons we don’t know, the diagnosis was delayed for seven hours.

The goal of the Canadian study was to measure all kinds of medical errors, not to estimate the death rate from erroneous or late diagnoses. The sample size wasn’t big enough for that. Had nobody in the study sample died, would that mean that ERs never make fatal errors? Obviously not.

The AHRQ report misused this single death to estimate a death rate across the entire U.S. Dividing one death by 503 patients, the researchers estimate a death rate of 0.2%. They then multiply 0.2% by total annual ER visits in the U.S.—130 million—and come up with 250,000 deaths.

For the full commentary, see:

Kristen Panthagani. “A Study Sounds a False Alarm About America’s Emergency Rooms.” The Wall Street Journal (Friday, Dec. 30, 2022): A17.

(Note: ellipsis added.)

(Note: the online version of the commentary has the date December 29, 2022, and has the same title as the print version.)

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