Variation in cardiologists' propensity to test and treat: is it associated with regional variation in utilization?

BACKGROUND: Regional variation in healthcare utilization, including cardiac testing and procedures, is well documented. Some factors underlying such variation are understood, including resource supply. However, less is known about how physician behaviors and attitudes may influence variation in utilization across regions. METHODS AND
RESULTS: We performed a survey of a national sample of cardiologists using patients vignettes to ascertain physicians' self-reported propensity to test and treat patients with cardiovascular problems, computing a Cardiac Intensity Score for each physician based on his/her responses intended to measure the physician's propensity to recommend high-tech and/or invasive tests and treatments. In addition, we asked under what circumstances they would order a cardiac catheterization "for other than purely clinical reasons." For some survey items, there was substantial variation in physician responses. We found that the Cardiac Intensity Score was associated with 2 measures of population based healthcare utilization measured within geographic regions, with a stronger association with general healthcare spending than with delivery of cardiac services. Although nearly all physicians denied ordering a potentially unnecessary cardiac catheterization for financial reasons, some physicians acknowledged ordering the test for other reasons, including meeting patient and referring physician expectations, meeting peer expectations, and malpractice concerns. More than 27% of respondents reported ordering a cardiac catheterization if a colleague would in the same situation frequently or sometimes, and nearly 24% reported doing so out of fear of malpractice. These 2 factors were significantly associated with the propensity to test and treat, but only fear of malpractice was associated with regional utilization.
CONCLUSIONS: Variability in cardiologists' propensity to test and treat partly underlies regional variation in utilization of general health and cardiology services. The factor most closely associated with this propensity was fear of malpractice suits. This factor may be an appropriate target of intervention.