Stress testing is a cornerstone in the evaluation of patients with possible symptoms of ischemic heart disease. The use of stress tests, and stress tests with imaging in particular, has increased over time raising concerns for inappropriate use that may include screening stress tests in asymptomatic patients. This study evaluated trends in the use of stress testing between 1993 and 2010 in the United States using data from the National Ambulatory Medical Care Survey (NAMCS) and National Hospital Ambulatory Medical Care Survey (NHAMCS). The primary outcome was the referral or performance of a stress test, with a subgroup evaluation of stress testing with imaging. Diagnosis codes and reasons for office visits were identified including the presence or absence of chest pain. Finally, the study evaluated the appropriateness of stress tests using appropriate use criteria that were collaboratively developed by a number of cardiovascular professional societies. Use of stress testing increased during the study period (28 per 10000 visits in 1993-1995 up to 45 per 10000 visits in 2008-2010), however this trend did not reach statistical significance when adjusted for patient and provider characteristics (p=0.134). The proportion of stress tests performed with imaging increased from 59% to 87% over the same timeframe and this trend was not explained by patient or provider characteristics. Appropriateness assessment determined 30% of the stress tests with imaging were inappropriate (i.e. no anticipated patient benefit) as compared with 14% of those without imaging.

Conclusions: Stress testing with imaging in the U.S. has increased at a rate that is not explained by changes in patient characteristics with nearly a third of these tests being considered inappropriate, consistent with procedural overuse. Given the challenges of assessing symptom burden from structured data fields taken from visit codes, incorporation of patient-reported symptom burden may guide a more nuanced understanding of potential overuse of stress testing in future studies.

Summarized by Javier A. Valle and Steven M. Bradley

Ladapo, J.A., S. Blecker, and P.S. Douglas, Physician Decision Making and Trends in the Use of Cardiac Stress Testing in the United States: An Analysis of Repeated Cross-sectional Data. Ann Intern Med, 2014. 161(7): p. 482-90.