To the Editor In their recent article, Schiff and colleagues1 computed the rate of malpractice claims filed against adult primary care physicians (PCPs) in Massachusetts. They found an annual rate of 3.3% (roughly 110 cases per year for 3305 physicians), noting that the rate was remarkably stable over the 5-year study period.
A lawsuit rate of 3.3% per year may not seem like much. (Hyman and Sage2 proclaimed it a relatively “modest rate” in their Invited Commentary on the article by Schiff et al.1) But annual rates convey a false sense of well-being. A more meaningful indicator of risk is the career likelihood of a malpractice claim. Using the following binomial probability formula:1 – (1 – λ)t, where λ is the annual risk of suit (eg, Schiff and coauthors’ rate of 0.033) and t is the duration of a medical career (eg, 40 years), I calculate that the probability of a Massachusetts PCP being sued at least once during his or her career as 74%. The binomial rests on a few assumptions: the annual risk of suit is the same each year, all PCPs face the same risk, and the risk to physicians each year is independent to what happened to them in any earlier year. While it is anticipated that reality will depart to some extent from the probability model, a 74% chance of suit, even as a first approximation, suggests that many PCPs will feel pressure to practice medicine defensively. A noteworthy contribution, then, is the authors’ identification of the breakdowns points in the process of care that most often result in legal liability.