Physician cognitive processing as a source of diagnostic and treatment disparities in coronary heart disease: results of a factorial priming experiment.

Literature on health disparities documents variations in clinical decision-making across patient characteristics, physician attributes, and among health care systems. Using data from a vignette-based factorial experiment of 256 primary care providers, we examine the cognitive basis of disparities in the diagnosis and treatment of coronary heart disease (CHD). We explore whether previously observed disparities are due to physicians (1) not fully considering CHD for certain patients or (2) considering CHD but then discounting it. Half of the physicians in the experiment were primed with explicit directions to consider a CHD diagnosis, and half were not. Relative to their unprimed counterparts, primed physicians were more likely to order CHD-related tests and prescriptions. However, the main effects for patient gender and age remained, suggesting that physicians treated these demographic variables as diagnostic features indicating lower risk of CHD for these patients. This finding suggests that physician appeals to perceived base rates have the potential to contribute to the further reification of socially constructed health statistics.