Shining a light on medical errors

Lucian Leape
Lucian Leape

Lucian Leape has made a career out of other people’s mistakes. Over the past three decades, his research has focused largely on strategies for reducing those all-too-common errors that kill tens of thousands of patients every year.

Leape began looking into medical errors as part of the Harvard Medical Practice Study, which examined the rates and root causes of malpractice in more than 50 New York hospitals during the 1980s. After analyzing nearly 30,000 patient records, the researchers found that roughly 4 in every 100 patients were injured as a result of their hospital stay, and two-thirds of those injuries happened because of a preventable error.

Leape and his colleagues also discovered that the malpractice system meant to address these problems was badly out of sync. On the one hand, there was a large number of “false positives”—malpractice claims against innocent doctors. On the other, there was an even bigger problem with “false negatives”—patients harmed by negligent care who had never filed any malpractice claim.

His research led Leape to the Human Factors Engineering literature on preventing errors through system design, and in “Error in Medicine,” a seminal 1994 paper published in the Journal of the American Medical Association, he proposed its application to healthcare. His policy prescription: Change some of medicine’s unexamined standard operating procedures—adopt checklists instead of individual memorization, for example, or reduce sleep deprivation. “Errors must be accepted as evidence of system flaws not character flaws. Until and unless that happens, it is unlikely that any substantial progress will be made in reducing medical errors.”

* * * * *

Is there an event, person, or discovery in Harvard School of Public Health history that you’d like to read about? Send your suggestions to

Back to centennial moments homepage