While studies using Medicare Part B data indicate a decline in outpatient imaging utilization, a new study suggests a different trend in the commercially insured patient population.

Using the Truven Health Analytics MarketScan® database, a group of researchers from Boston University and the Department of Veteran Affairs looked at utilization of and payments for CT, MRI, PET and ultrasound between 2007 and 2011.

The database included inpatient facility and professional encounters as well as outpatient encounters in physician offices, hospital and other outpatient facilities, and emergency department visits. The authors acknowledge that the data sample did not necessarily contain the same commercially insured patients through the study period, but suggest that it was a fair representation of all adults aged 19 to 64 years with commercial insurance in the U.S.

In the outpatient settings, Horny et al found single and low double-digit increases in service in all four modalities between 2007 and 2009, peaking in 2009 at 106 percent (CT), 105 percent (MRI), 111 percent (PET) and 113 percent (ultrasound) of 2007 adjusted baseline levels.

Between 2009 and 2010, utilization of outpatient and inpatient imaging declined in all modalities in the commercial population, with the exception of inpatient PET.  In fact, CT and MRI declined by 1 percent below 2007 baseline levels. In 2011, outpatient imaging of CT, MRI increased, with PET use declining slightly.

Inpatient imaging resumed its growth pattern in MRI, CT and ultrasound between 2010 and 2011, but there was a decline in PET imaging.

Adjusted payments for outpatient imaging followed a pattern similar to utilization, growing in all modalities from 2007 and 2009, declining in 2010, and resuming growth between 2010 and 2011.

Study key findings include:

• Contrary to the downward utilization trends in the Medicare population, utilization of CT, MRI and ultrasound increased in 2011 in the commercially insured population following a brief downturn in 2010.

• Introduction of new CPT codes for combined abdomen and pelvis CT scans apparently succeeded in efforts to cut payments for outpatient CT scans despite increases in utilization.

“Policymakers and insurers will be challenged to devise strategies for keeping imaging utilization and payments under control as millions of previously uninsured Americans become enrolled in commercial insurance plans available through federal a d state health exchanges and through Medicaid expansions now being created and implemented under the Affordable Care Act,” the authors conclude.