Underuse and overuse of diagnostic testing for coronary artery disease in patients presenting with new-onset chest pain

PURPOSE: To determine the extent of overuse and underuse of diagnostic testing for coronary artery disease and whether the socioeconomic status, health insurance, gender, and race/ethnicity of a patient influences the use of diagnostic tests. SUBJECTS AND METHODS: We identified patients who presented with new-onset chest pain not due to myocardial infarction at one of five Los Angeles-area hospital emergency departments between October 1994 and April 1996. Explicit criteria for diagnostic testing were developed using the RAND/University of California, Los Angeles, expert panel method. They were applied to data collected by medical record review and patient questionnaire. RESULTS: Of the 356 patients, 181 met necessity criteria for diagnostic cardiac testing. Of these, 40 (22%) failed to receive necessary tests. Only 7 (3%) of the 215 patients who received some form of cardiac testing had tests that were judged to be inappropriate. Underuse was significantly more common in patients with only a high school education (30% vs 15% for those with some college, P = 0.02) and those without health insurance (34% vs 15% of insured patients, P = 0.01). In a multivariate logistic regression model, only the lack of a post-high school education was a significant predictor of underuse (odds ratio 2.2, 95% confidence interval 1.0 to 4.4). CONCLUSION: Among patients with new-onset chest pain, underuse of diagnostic testing for coronary artery disease was much more common than overuse. Underuse was primarily associated with lower levels of patient education.