Malpractice liability caps don't reduce defensive medicine, study says

Caps on malpractice liability damages don't reduce the likelihood that physicians will practice defensive medicine, according to a recent study in Health Affairs.

In what the study's authors labeled a "counterintuitive finding," the presence of caps on damages was actually associated with greater use of some healthcare services. The authors speculated that this could be an example of "reverse causality," in which a high prevalence of concern about malpractice and defensive medicine among physicians might make a state more likely to adopt a damages cap.

Rather than the presence of malpractice caps or tort reform laws in a state, a much more accurate predictor of defensive medicine is simply an individual physician's level of concern about being slapped with a malpractice lawsuit, according to the study, which was led by researchers from the Center for Studying Health System Change.

"This study found that physicians who reported concern about their malpractice risk and who evaluated patients visiting their offices with chest pain, headache, or lower back pain were significantly more likely to order certain diagnostic tests, a pattern consistent with the practice of defensive medicine," the authors write.

To obtain data for the study, researchers coupled physicians' responses to a 2008 survey on malpractice concern with Medicare claims data for the patients those physicians treated from 2007 to 2009. The study's sample included nearly 1.9 million patients who received services from 3,469 physician survey respondents during that timeframe.

To quantify defensive medicine, the researchers examined three factors: whether a patient received diagnostic imaging services, was referred to the emergency department or was admitted to a hospital. The analysis included only patients who visited physicians with a complaint of chest pain, headache or lower back pain. Researchers chose those conditions because they represent a wide range of potential underlying problems and because physicians have "considerable discretion" in responding to those complaints, according to the study.

The study's findings suggest that, to reduce defensive medicine, it may be more effective to focus on physicians' perceptions of legal risk and the factors driving those perceptions, rather than tort reform. Prior studies have shown physicians "greatly overestimate their risk of being sued," according to the study.

"Physicians’ extreme dread of malpractice litigation may stem from their perception that it is unpredictable, uncontrollable, and potentially disastrous both financially and psychologically," the authors write.

While that perception is likely widespread among doctors, consider the following data from previous studies that the authors cite to support their assertion that physicians overestimate malpractice risk:

• Only about one in 50 injuries caused by negligence result in a claim.

• Lawsuits are virtually never settled for amounts that exceed physicians' insurance policy limits, meaning there's little personal financial risk for doctors.

• Claims are resolved in ways that are "concordant with their merit" about 75% of the time.

• Malpractice plaintiffs lose four out of five trials.

But the authors don't seem too confident that this data will change how physicians perceive their exposure to malpractice risk, noting that their research "suggests that physicians' attitudes may be hard to align with their actual risk."

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