Greatest impact of safe harbor rule may be to improve patient safety, not reduce liability claims paid by physicians.

"Safe harbor" legislation that provides liability protection to physicians when they follow designated guidelines is often proposed as a way to reform the malpractice system while improving patient safety. However, published evidence provides little policy guidance on implementing safe harbors. With the support of an Agency for Healthcare Research and Quality planning grant, we conducted an empirical analysis of closed liability claims in Oregon to determine the potential effects of hypothetical safe harbor legislation. We found that such legislation would have changed the liability outcome in favor of the physician defendant in only 1 percent of 266 claims from the period 2002-09 that we reviewed. Nevertheless, if safe harbors can induce greater physician adherence to care guidelines, they have the potential to improve patient safety. Implementing safe harbor legislation, however, requires overcoming a number of hurdles, including selecting and updating approved guidelines, obtaining broad stakeholder support, and withstanding challenges to the legal validity of the legislation. More experimentation with safe harbors is needed to determine their effects on the performance of the liability system and on health care quality and costs.