All final year NZ medical students in 2014 and 2015 (n=888) were invited to participate in the Bias and Decision-Making in Medicine (BDMM) study, a cross-sectional online investigation that examined ethnic bias (Māori compared with NZ European) among medical students and associations with clinical decision-making. Key components included two chronic disease vignettes (CVD and depression) with randomised patient ethnicity (Māori or NZ European) and questions on patient management, implicit bias measures (an ethnicity preference Implicit Association Test [IAT] and an ethnicity and compliant patient IAT), and explicit ethnic bias questions. One-third of the students (n=302) participated in the survey (34% response rate). Linear regression analysis identified implicit and explicit ethnic bias favouring NZ Europeans. No significant differences in clinical decision-making by patient ethnicity were observed for the CVD vignette. The analysis also failed to identify any differential associations by patient ethnicity between any measures of ethnic bias (implicit or explicit) and patient management responses in the CVD vignette. However, in the depression vignette, the ranking of recommended treatment options differed by patient ethnicity and there was explicit preference for NZ Europeans, reflected by increased reporting that NZ European patients would benefit from treatment but not Māori (slope difference 0.34; 95% CI, 0.08 to 0.60; p=0.011), although this was the only significant finding in these analyses.
