Patients' gender affected physicians' clinical decisions when presented with standardized patients but not for...

To compare physicians' treatment and referral decisions for total knee arthroplasty (TKA) for standardized patients with matching paper patients.

Sixty-seven physicians (38 family physicians and 29 orthopedic surgeons) performed blinded assessments of two standardized patients (one man and one woman) with moderate knee osteoarthritis and otherwise identical clinical scenarios differing only in gender, and consented to including their data. Standardized patients recorded physicians' recommendations (yes/no) to refer for, or perform, TKA. Sixty physicians provided their treatment recommendations to matching paper patients.

Recommendation rates for both the male and the female standardized patients (67% and 32%, respectively) were lower compared with the matching paper patients (80% and 67%, respectively). Physicians were more likely to recommend TKA to a man than to a woman when presented with standardized patients (odds ratio, 4.2; 95% confidence interval [CI]=2.4-7.3; P<0.001). In contrast, patients' gender did not affect the same physicians' recommendations regarding referral for, or performing, TKA for the matching paper patients (odds ratio, 2.0; 95% CI=0.9-4.6; P=0.101).

Unlike their treatment recommendations for standardized patients, the same physicians' treatment and referral decisions for paper patients were not influenced by patients' gender, suggesting that paper patients are not a sensitive method of assessing physician bias.