Providers blunt skyrocketing use of CT for pulmonary embolism, but numbers still climbing

The delivery of chest CT imaging for suspected pulmonary embolism has continued to climb in the U.S. despite concerns of overuse, according to a study published Friday.

Since its introduction in the early 2000s, computed tomographic pulmonary angiography, or CTPA, has been embraced by emergency department and hospital physicians. But that’s led to unnecessary and wasteful diagnostic testing, experts noted in JAMA Network Open.

Since then, providers have implemented interventions to try and stem the tide. But CTPA use is still rising—albeit at a slower pace—based on an analysis of millions of patient encounters across multiple hospital systems.

“Efforts to combat overuse have not led to a reduction in imaging to screen for PE and at best may have contributed to its slower growth in recent years,” Ralph Wang, MD, with the Department of Emergency Medicine at the University of California, San Francisco, and colleagues from several other institutions wrote Nov. 20.

For their study, Wang et al. analyzed more than 52.3 million person-years of follow-up data, gathered across seven different integrated health systems that also offer health insurance plans. All told, the records covered a span of 12 years ending in 2016, with each study year including between 3.6 to 4.8 million American adults.

The research team sought to analyze trends in CTPA across hospital systems, along with the delivery of chest CT and ventilation-perfusion scans. Also referred to as “V/Q,” the latter was the typical go-to nuclear medicine examination for pulmonary embolism, prior to the early aughts, according to the authors.

Bottom line: Chest CT use leapt 66.3% during the study period, at an annual growth rate of 4.4% each year. Meanwhile, CTPA delivery skyrocketed by 450% (or 16.3% per year) at the same time, while V/Q use fell 47.1% (or 4.9% annually), with a steady decline over 12 years. CT pulmonary angiography’s meteoric rise appeared to halt during the tail end of the study period. Between 2004 to 2006 it had climbed roughly 44%. But from 2010 to 2016, it slowed to between 3%-4% among all age groups.

Efforts to address CTPA misuse have included the creation of decision rules for pulmonary embolism testing, relying on risk stratification algorithms, Wang and colleagues noted. Strategies have also been widely disseminated through campaigns such as Choosing Wisely. And five societies, including the American College of Radiology, have published guidelines promoting the avoidance of CTPA for patients with a low-probability of pulmonary embolism and a negative D-dimer test (or who are negative based on PE rule-out criteria).

However, the research team’s conclusions may cast doubt on the overall success of this movement.

“Efforts to combat overuse have not been completely successful as reflected by ongoing growth, rather than decline, of chest CT use,” Wang et al. advised. “Whether the observed imaging use was appropriate or was associated with improved patient outcomes is unknown.”

Read more of their analysis in JAMA Network Open here.