Richard Menger, a neurosurgery resident at Louisiana State University’s Health Sciences Center, tells a surprising tale in an article for the Foundation for Economic Education: how a rule meant to reduce doctors’ fatigue made neurosurgery less safe.

The rule was made with good intentions. Tired doctors are more likely to make mistakes, so by limiting the hours medical residents are permitted to work in a given week, there should be fewer tired doctors making fewer mistakes.

The good intentions didn’t lead to good results, however:

A landmark study in 2012 found that duty hour restrictions actually caused more complications. Preventable or avoidable bad outcomes increased because of disruptions in continuity of care.

Because each physician works fewer hours, they have to hand off patients to other doctors, which can lead to mistakes even more serious than those caused by fatigue.

If you’ve ever played the game “Telephone” in school, you know how this happens. The more people passing a message in the telephone game, the more warped the message becomes. Similarly, handing off patients from one doctor to another disrupts care and leaves room for mistakes.

In addition, Menger points out, surgeries are more likely to be dropped when hours restrictions are in place. Particularly in neurosurgery, where surgeries can range from 4 to 10 hours, restricting hours for residents means that residents perform fewer surgeries and get less experience.

This puts residents in a difficult situation:

If the resident is close to the duty hour cap, she could be faced with a terrible choice: she can make the unethical decision to go home, abide by the rules, and miss the opportunity to learn how to do a unique and challenging procedure that takes a lifetime to master — or she can make the unethical decision to lie about her duty hours.

This is just one example of how policies with good intentions can have unintended consequences, especially in health care. Check out the video below on FDA approval to learn more: