An International Comparison of Physicians' Judgments of Outcome Rates of Cardiac Procedures and Attitudes toward Risk, Uncertainty, Justifiability, and Regret

Objective. Compare U.K. and U.S. physicians' judgments of population probabilities of important outcomes of invasive cardiac procedures; and values held by them about risk, uncertainty, regret, and justifiability relevant to utilization of cardiac treatments. Design. Cross-sectional study. Setting. University hospital and VA medical center in the United States; two teaching hospitals in the United Kingdom. Participants. 171 housestaff and attendings at U.S. teaching hospitals; 51 physician trainees and consultants at U.K. hospitals. Measures. Judgments of probabilities of severe complications and deaths due to Swan-Ganz catheterization, cardiac catheterization, percutaneous transluminal coronary angioplasty (PTCA), and coronary artery bypass grafting (CABG); judgments of malpractice risks for case vignettes; Nightingale's risk-aversion instrument; Gerrity's reaction-to-uncertainty instrument; questions about need to justify decisions; responses to case vignettes regarding regret. Results. The U.S. physicians judged rates of two bad outcomes of cardiac procedures (complications due to cardiac catheterization; death due to CABG) to be significantly higher (p ≤ 0.01) than did the U.K. physicians (U.S. medians, 5 and 3.5, respectively; U.K. medians 3 and 2). The median ratio of (risk of malpractice suit I error of omission)/(risk of suit I error of commission) judged by U.K. physicians, 3, was significantly (p = 0.0006) higher than that judged by U.S. physicians, 1.5. The U.K. physicians were less often risk-seeking in the context of possible losses than the U.S. physicians (odds ratio for practicing in the U.K. as a predictor of risk seeking 0.3, p = 0.003). The U.K. physicians had significantly more discomfort with uncertainty than did the U.S. physicians, as reflected by higher scores on the stress scale (U.K. median 48, U.S. 42, p = 0.0001) and the reluctance-to-disclose-uncertainty scale (U.K. 40, U.S. 37, p < 0.0001) of the Gerrity instrument. There was no clear international difference in perceived need to justify decisions, or in regret. Conclusions. The results were not clearly consistent with the uncertainty hypothesis that international practice variation is due to differences in judged rates of outcomes of therapy or with the imperfect-agency hypothesis that practice variation is due to differences in physicians' personal values. The causes and implications of practice variations remain unclear.