Referrals in acute coronary events for CARdiac catheterization: The RACE CAR trial.

Background: Women with acute coronary syndromes have lower rates of cardiac catheterization (CC) than men.

Objective: To determine whether sex⁄gender, age, risk level and patient preference influence physician decision making to refer patients for CC.

Methods: Twelve clinical scenarios controlling for sex⁄gender, age (55 or 75 years of age), Thrombolysis in Myocardial Infarction risk score (low, moderate or high) and patient preference for CC (agreeable or refused⁄no preference expressed) were designed. Scenarios were administered to specialists across Canada using a web-based computerized survey instrument. Questions were standardized using a five-point Likert scale ranging from 1 (very unlikely to benefit from CC) to 5 (very likely to benefit from CC). Outcomes were assessed using a two-tailed mixed linear regression model.

Results: Of 237 scenarios, physicians rated men as more likely to benefit from CC than women (mean [± SE] 4.44±0.07 versus 4.25±0.07, P=0.03), adjusted for age, risk and patient preference. Low-risk men were perceived to benefit more than low-risk women (4.20±0.13 versus 3.54±0.14, P<0.01), and low-risk younger patients were perceived to benefit more than low-risk older patients (4.52±0.17 versus 3.22±0.16, P<0.01). Regardless of risk, patients who agreed to CC were perceived as more likely to benefit from CC than patients who were disagreeable or made no comment at all (5.0±0.23, 3.67±0.21, 2.95±0.14, respectively, P<0.01).

Conclusion: Canadian specialists' decisions to refer patients for CC appear to be influenced by sex⁄gender, age and patient preference in clinical scenarios in which cardiac risk is held constant. Future investigation of possible age and sex⁄gender biases as proxies for risk is warranted.