CT growth comes to a halt, except in the ED

After growing rapidly for years, total Medicare CT utilization declined by 1.7 percent in 2010, according to a study published in the Journal of the American College of Radiology.

A detailed analysis of where CT was being utilized showed that emergency departments (ED) were the only locations with continued growth, and without this increase, the overall decline in Medicare CT utilization would have been 4.7 percent, according to David C. Levin, MD; Vijay M. Rao, MD; and Laurence Parker, PhD, all from Thomas Jefferson University Hospital in Philadelphia.

“This downturn should help alleviate previous concerns about overly rapid CT growth,” wrote the authors.

Levin and colleagues used nationwide Medicare Part B databases for 2000 through 2010 for their analysis. All diagnostic CT Current Procedural Terminology codes, including CT angiography, were selected.

Results revealed a general trend of rapid CT growth from 2000 to 2006, which then began to flatten out and peak by 2009. Total Medicare CT use was 325 per 1,000 in 2000 and grew to 637 per 1,000 in 2009, according to the authors. This represented a compound annual growth rate (CAGR) of 7.8 percent. The rate dropped for the first time in 2010, falling to 626 per 1,000.

From 2000 to 2009, the CAGRs for inpatient CT, hospital outpatient CT, private office CT and ED CT were 5.5, 5.1, 11.3 and 15.2 percent, respectively. All areas saw a drop in utilization in 2010 except for the ED, which saw another 8.4 percent increase in 2010.

The authors said the reasons for the changing utilization trends are not clear, but they listed a number of possible contributing factors:

  • Increased attention to radiation concerns could have made referring physicians more reluctant to obtain CT scans unless absolutely necessary;
  • Physicians could be more cost-conscious and trying to limit imaging use;
  • Physicians could be increasingly adhering to appropriateness criteria developed by the American College of Radiology (ACR) and the American College of Cardiology;
  • Educational campaigns, such as the Image Wisely and Image Gently campaigns from the ACR, could have reduced overuse;
  • Radiology benefits management employed by commercial payers could have shifted CT ordering patterns among referring clinicians, even though Medicare has not instituted a prior authorization program; and
  • The recession could have limited utilization.

“It seems probable that all the above factors, especially the first five, have played a role in the slowdown and then downturn in Medicare CT utilization,” wrote Levin and colleagues. “Whatever the reason, it seems that the rapid growth in CT that was causing concern a few years ago may have come to an end.” They added that any further attempts to curb CT use should be focused on the ED.