Influence of patient race on physician prescribing decisions: A randomized on-line experiment

Background: Prior research reports black patients have lower medication use for hypercholesterolemia, hypertension, and diabetes. Objective: To assess whether patient race influences physicians' prescribing. Design: Web-based survey including three clinical vignettes (hypercholesterolemia, hypertension, diabetes), with patient race (black, white) randomized across vignettes. Subjects: A total of 716 respondents from 5,141 eligible sampled primary care physicians (14% response rate). Interventions: None Measurements: Medication recommendation (any medication vs none, on-patent branded vs generic, and therapeutic class) and physicians' treatment adherence forecast (10-point Likert scale, 1-definitely not adhere, 10-definitely adhere). Results: Respondents randomized to view black patients (n=371) and white patients (n=345) recommend any medications at comparable rates for hypercholesterolemia (100.0% white vs 99.5% black, P=0.50), hypertension (99.7% white vs 99.5% black, P=1.00), and diabetes (99.7% white vs 99.7% black, P=1.00). Patient race influenced medication class chosen in the hypertension vignette; respondents randomized to view black patients recommended calcium channel blockers more often (20.8% black vs 3.2% white) and angiotensin-converting enzyme inhibitors less often (47.4% black vs 62.6% white) (P<0.001). Patient race did not influence medication class for hypercholesterolemia or diabetes. Respondents randomized to view black patients reported lower forecasted patient adherence for hypertension (P<0.001, mean: 7.3 black vs 7.7 white) and diabetes (P=0.05 mean: 7.4 black vs 7.6 white), but race had no meaningful influence on forecasted adherence for hypercholesterolemia (P=0.15, mean: 7.2 black vs 7.3 white). Conclusion: Racial differences in outpatient prescribing patterns for hypertension, hypercholesterolemia, and diabetes are likely attributable to factors other than prescribing decisions based on patient race.