We examined differences in demographic characteristics, likelihood of CAD, and decisions to treat with thrombolysis between participants assigned to black versus white patients using chi-square and t tests as appropriate. We compared mean IAT scores for various demographic groups using t tests. To look for relative disparity by race between diagnosis and treatment, we compared participants’ ratings of the likelihood that the chest pain was because of CAD (the diagnosis variable, 1–5 scale as above) with the likelihood of treating the patient with thrombolysis (the treatment variable, yes/no). To do this we put both the diagnosis and treatment variables on the same scale using z-scores. We then subtracted the treatment variable from the diagnosis variable to create a delta variable. A delta score of zero indicated that treatment was commensurate with diagnosis. A negative score indicated that treatment was more likely than diagnosis, and a positive score indicated that diagnosis was more likely than treatment. We used a one-way ANOVA to test whether diagnosis-treatment delta was different for black versus white patients.
