“Defensive medicine” has long been a favorite rationale for our health care costs. Indeed, in a recent survey of physicians in JAMA, trial lawyers were assigned the greatest responsibility for reducing health care costs: 60% of respondents thought they had a major role, followed by insurers (59%), pharma and device manufacturers (56%), hospitals (56%), and patients (52%). In contrast, only 36% of physicians thought physicians had a major role in cost control.
I’ve never been a huge fan of the defensive medicine hypothesis. First, several studies have suggested that only a very small percentage (around 3%) of total health care spending can be attributed to malpractice. Second, poor outcomes and allegations of malpractice can arise from errors of commission as well as of omission. A fatal allergic reaction to an antibiotic prescribed unnecessarily for a viral illness could as easily open a provider up to a liability claim as not doing an unnecessary CT scan for a child with trivial head injury, so I would imagine someone fearful of a lawsuit would hesitate to do both. Most important, in my own experience (admittedly skewed by working in academic centers), overuse appears to be driven far more strongly by factors such as the desire for more complete information before making decisions (more on that in a subsequent blog), and by financial incentives.
A recent study, though, provides what appears to be compelling evidence of the effect of fear of malpractice on use of diagnostic tests. An article in the August issue of Health Affairs linked physicians’ responses regarding their levels of malpractice concern as reported in the 2008 Health Tracking Physician Survey to Medicare Parts A and B claims for the patients they treated during the study period, 2007–09, focusing on use of various diagnostic tests for complaints of chest pain, headache, or lower back pain. The investigators found higher rates of imaging by physicians who had reported high vs. low concern about malpractice on the survey, although the magnitudes were modest. This would suggest that defensive medicine may be a significant contributor to overall healthcare costs. However, the study undercuts the assertion that moves to limit malpractice claims would help – there was no association between diagnostic testing and various measures of actual state malpractice risk, only with the physician’s reported subjective level of concern.
Which raises several questions. Where does the fear arise from, if not from the actual climate of the state within which the physicians practice? Is it truly a fear of liability, or is that just an expression of an underlying tendency to place a premium on diagnostic certainty? Providers tend to fall into one of two camps – “test minimizers” and “risk minimizers” – based on their tolerance for uncertainty. In either case, if individual provider attitudes override public policy, how can we address this factor in the effort to control costs? At the very least, it suggests that the doctors have at least as much responsibility as the trial lawyers.