Steven Farmer (Center for Healthcare Innovation and Policy Research, George Washington University, Washington, DC, USA) and others report in JAMA Cardiology that, following the adoption of damage caps—which limit how much a patient receives in a malpractice suite—physicians refer fewer patients for invasive testing and refer fewer patients for revascularisation. This suggests physicians tolerate greater clinical uncertainty in coronary artery disease testing and treatment if they face a lower malpractice risk.
Farmer et al comment that physicians are known to practice “defensive medicine”, which includes “ordering marginally beneficial tests and interventions”, to prevent malpractice suites. They add whether reducing the risk of malpractice would lead to a decrease in the use of defensive medication is “a key policy question”. “Many states have adopted non-economic damage caps, which limit awards to compensate malpractice plaintiffs for ‘pain and suffering’”, the authors observed.
Given that imaging and invasive diagnostic tests “are often cited as overused for defensive measures”, Farmer et al report that the aim of the present study was to determine if physicians facing lower malpractice risk would be willing to tolerate more clinical uncertainty surrounding coronary artery disease. Therefore, they compared physician-specific changes in coronary artery disease testing and treatments between 2003 and 2009 in nine US states that adopted damage caps with 20 US states that did not adopt such changes.
Of 75,801 physicians included in the retrospective analysis, 36,647 (about half) practised in new cap states. Compared with physicians in no cap states, after adoption of damage caps, physicians working in new cap states ordered fewer initial angiograms and referred fewer patients (following stress testing) to angiography. Overall, this led to a significant 21% reduction (p=0.01) in angiography rates. However, the number of ischaemic evaluations did not change as new cap physicians ordered more initial stress tests. The authors comment: “Additionally, [in new cap states] fewer patients progressed from any ischaemic evaluation to revascularisation (-26%; p=0.01). The lower revascularisation rates are driven by fewer percutaneous coronary interventions (PCI); coronary artery bypass grafting (CABG) rates did not change.”
Concluding, they note: “We found evidence that physicians altered their coronary artery disease testing and intervention following adaption of damage caps”. “These findings suggest that physicians are willing to tolerate greater uncertainty in coronary artery disease testing and treatment if they face lower malpractice risk,” Farmer et al add.
