Cardiac stress imaging more likely among patients treated by physicians who bill for these tests

Issue: December 2011

Patients who were billed for technical fees, professional fees or both were more likely to undergo nuclear stress testing and stress echocardiography testing after revascularization compared with patients who were not billed, researchers wrote in a recent study.

Bimal R. Shah, MD, MBA, of the Duke Clinical Research Institute and division of CV medicine at Duke University Medical Center, and colleagues collected data from November 2004 to June 2007 on 17,847 patients who had coronary revascularization and an index cardiac outpatient visit more than 90 days after the procedure. The main outcome measure was incidence of nuclear and echocardiographic stress test within 30 days of an index cardiac-related outpatient visit, and the association between physician billing and use of stress testing was evaluated by logistic regression models. Researchers classified physicians by whether they billed for technical and professional fees, professional fees only or neither.

Nuclear stress testing associated with the index cardiac-related outpatient visit had a 30-day incidence of 10.4% (95% CI, 10.1-10.8) vs. 1.8% (95% CI, 1.6-2) for stress echocardiography. Results showed patients were more likely to undergo nuclear stress testing (22.1%; 95% CI, 20.5-23.7) and stress echocardiography (3.4%; 95% CI, 2.7-4.1) if they had any potential cardiac symptom-related indication for their index outpatient visit vs. those without symptoms (nuclear testing: 8.5%; 95% CI, 8.1-8.9; stress echocardiography: 1.6%; 95% CI, 1.4-1.8).

Researchers found a cumulative incidence of nuclear stress testing of 12.6% (95% CI, 12-13.2) vs. 8.8% (95% CI, 7.5-10.2) for those who billed for professional fees only and 5% (95% CI, 4.4%-5.7%) for those who billed for neither, whereas cumulative incidence of testing with stress echocardiography was 2.8% (95% CI, 2.5-3.2) among physicians who billed for technical and professional fees, 1.4% (95% CI, 1-1.9) among those who billed for professional fees only and 0.4% (95% CI, 0.3%-0.6%) for those who billed for neither. Overall, cardiologists were more likely to conduct stress tests than primary care physicians.

“The study by Shah et al highlights the principal risk of in-office imaging,” Brent K. Hollenbeck, MD, MS, of the department of urology, and Brahmajee K. Nallamothu, MD, MPH, of the department of internal medicine, both at the University of Michigan, wrote in an accompanying editorial. “By examining this phenomenon in a clinical context generally considered to be ‘inappropriate’ — namely, routine cardiac stress imaging after coronary revascularization — the investigators have demonstrated the persistence of financial conflicts of interest as a driver of utilization. The truism ‘if you provide a service, you’re more likely to provide a service’ apparently has not changed over the years.”

Hollenbeck BK. JAMA 2011;2028-2030.

Shah BR. JAMA. 2011;306:1993-2000.

Disclosure: Drs. Shah, Hollenbeck and Nallamothu report no relevant financial disclosures.

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