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More CT pulmonary angiogram orders reduces diagnostic yield

Physicians who ordered more CT pulmonary angiogram scans experienced a markedly decreased proportion of positive results, according to new research published in JAMA Internal Medicine.

“Pulmonary embolism can be life-threatening and, when suspected, is usually investigated by computed tomographic pulmonary angiogram (CTPA),” Jaron Chong, MD, from the department of radiology at the McGill University Health Centre, Montreal, and colleagues wrote. “Concerns related to overutilization and harmful ionizing radiation have identified CTPA as an area in need of resource stewardship.”

Chong and colleagues conducted a retrospective review of all CTPAs performed between September 2014 to January 2016 at an academic teaching hospital in Canada to investigate the associations between CTPA diagnostic yield and physician specialty, years in practice, physician sex and total number of studies ordered per physician. The study included 1,394 exams (14.3% positive and 85.7% negative) ordered by 182 physicians.

Using a generalized estimating equations approach, they found that as the total number of scans ordered per physicians rose, the probability of a positive CTPA declined and continued to decline for each additional 10 studies ordered (OR = 0.76; 95% CI, 0.73-0.79).

A higher diagnostic yield was observed in patients with increasing age (OR = 1.02 per year; 95% CI, 1.01-1.03). Diagnostic yield was not statistically significantly associated with physician years of experience (OR = 1.01; 95% CI, 0.99-1.02), physician sex (OR = 1.14; 95% CI, 0.79-1.63) or studies originating from the ED (OR = 1.11; 95% CI, 0.75-1.65).

Limiting the investigation to only studies conducted by ED physicians showed that out of 974 examinations, 123 were positive, and the OR for a positive CTPA for each additional 10 scans ordered declined similarly to the overall analysis (OR = 0.74; 95% CI, 0.71-0.78).

The association between a greater number of CTPA scans ordered and lower positive results “may reflect a fundamental relationship between individual physician overutilization and decreasing diagnostic yield, and is deserving of greater attention,” Chong and colleagues concluded. “Peer-relative rates of utilization are easily quantified from electronic databases, and can identify physicians most likely to benefit from individual performance feedback and decision support tools.”

In an accompanying editorial, Deborah Grady, MD, MPH, and Michael Incze, MD, MSEd, both from the department of medicine at the University of California, San Francisco, wrote that the “thought provoking” findings by Chong and colleagues demonstrate how physicians can use electronic health records (EHRs) as a practice-improvement coach to deter overuse of CTPAs and improve patient care.

EHRs deliver real-time performance metrics which can be used to inform interventions, such as personalized decision support tools, they wrote.

“Targeted interventions through the [EHR] could potentially reduce alert fatigue by decreasing the overall number of reminders for physicians,” Grady and Incze wrote. – by Alaina Tedesco

Disclosure: The authors report no relevant financial disclosures.