Diagnostic imaging utilization in Massachusetts: 3 key trends

A team of researchers examined diagnostic imaging utilization trends in Massachusetts from 2009 to 2013 for a recent study in the Journal of the American College of Radiology.

“Prior studies noted that utilization growth for diagnostic imaging began to decline around 2009, perhaps a reflection of the impact of regulatory changes that addressed excess Medicare spending growth, such as those in the Deficit Reduction Act of 2007, and efforts to reduce radiation exposure like the Choosing Wisely initiative,” wrote Stephen Flaherty, BS, MBA, from the Bouvé College of Health Sciences at Northeastern University in Boston, and colleagues. “More recent work has identified signs of increasing utilization after the slowdown in imaging utilization from 2009 to 2011. However, there is a lack of recent research with more current data (e.g., after 2011) that report on statewide or national trends in utilization across modalities for commercially insured populations.”

The authors used the Massachusetts All-Payer Claims Database and CPT codes for their research. These are three key trends reported in their findings:

1. Overall utilization of diagnostic imaging did not significantly change from 2009 to 2013.

“Despite annual variability, the number of diagnostic imaging claims per commercially insured Massachusetts resident did not change substantially over the study period, with a 5-year growth trend of 0.6 percent,” the authors wrote.

The number of nonimaging claims, meanwhile, had a 5-year average growth rate of 7 percent.  

2. Spending on diagnostic imaging fell from 2009 to 2013.

Flaherty et al. noted that total spending on diagnostic imaging, when adjusted for inflation, was down from 2009 to 2013. “This is primarily a result of declining payment per procedure for most modalities and was also heavily influenced by CT coding changes,” the authors wrote. “Imaging claims accounted for 10 percent of total spending in 2009 and fell to 7 percent of total spending by 2013.”

Another potential reason for this shift, the authors added, could be an “increased use of lower-cost providers.”

3. Utilization is up for MRI, ultrasound and x-ray.

The authors determined five-year trends for each modality. MRI (more than 3 percent), ultrasound (more than 4 percent) and x-ray (more than 3 percent) all trended up over that five-year period.  

“There were more examinations performed in 2013 in each of these modalities compared with 2009, despite a smaller commercially insured population,” the authors wrote. “The growth in these modalities was offset by declines in CT and NM utilization.”

Utilization of CT exams was down more than 9 percent from 2009 to 2013. Utilization of nuclear medicine (NM) exams was down more than 17 percent. The authors noted that a billing code change in 2011 played a significant role in these statistics.  

“CT abdomen and pelvis examinations (which make up nearly one-half of total CT volume) are typically performed together,” the authors wrote. “Before 2011, providers could bill for separate abdomen and pelvis charges. The coding change in 2011 that introduced the combined abdomen and pelvis charge influenced both utilization—when measured by number of claims—and spending, although there was little change in clinical practice as similar numbers of patients were getting abdomen and pelvis scans. CT utilization fell by nearly 30 percent as the two procedures became a single claim, and with payment for the combined code substantially less than the total of the previously billed individual codes, revenues in CT were 47 percent lower in 2011, falling from $295 million to $151 million.”

In addition, numerous NM billing codes were retired during the study period. New combined codes were introduced, which could have impacted utilization and spending related to NM exams.

Flaherty and colleagues also suspect that patient awareness about radiation exposure in medical imaging could have caused certain modalities to see dips in utilization. “Additional research is needed to determine if the choice of modalities for specific clinical indications did shift over time,” the authors wrote.