Computed tomography utilization in the North Carolina Medicaid population with a focus on "high exposure" patients, 2007-2012.

BACKGROUND: We examined trends in utilization of computed tomography (CT) among Medicaid enrollees in North Carolina, the clinical setting in which those CT scans were performed, and the number of enrollees known to have undergone 10 or more scans in a given year. METHODS: North Carolina Medicaid claims were analyzed to determine the number of CT studies performed between January 1, 2007, and December 31, 2012. We assessed the number of "high exposure" patients--those who received 10 or more CT scans in a given calendar year--and divided this group into patients with a diagnosis of cancer and patients without a diagnosis of cancer. We also determined the type of site at which each CT scan was performed. RESULTS: Over the 6-year period 2007-2012, the percentage of all enrollees who underwent any CT study ranged from 8.0% to 9.6% (126,082-177,425 enrollees). The number of CT scans performed annually increased from 2007 to 2009 and then plateaued. The number of high-exposure patients increased gradually, from 2,171 in 2007 to 4,017 in 2012. The majority of CT scans of high--exposure patients--150,241 of 251,052 (59.8%)--were performed in non office outpatient settings, such as emergency departments or urgent care centers. CONCLUSION: Although the number of CT scans performed annually in the North Carolina Medicaid population stabilized in the late 2000s (as did CT use nationally), the percentage of high-exposure patients has continued to rise. Physicians and patients need to be further educated in order to promote radiation safety and to decrease unnecessary radiation exposure.

With "big data" comes big responsibility: outreach to North Carolina Medicaid patients with 10 or more computed tomography scans in 12 months.

BACKGROUND: Patients are being exposed to increasing levels of ionizing radiation, much of it from computed tomography (CT) scans. METHODS: Adults without a cancer diagnosis who received 10 or more CT scans in 2010 were identified from North Carolina Medicaid claims data and were sent a letter in July 2011 informing them of their radiation exposure; those who had undergone 20 or more CT scans in 2010 were also telephoned. The CT scan exposure of these high-exposure patients during the 12 months following these interventions was compared with that of adult Medicaid patients without cancer who had at least 1 CT scan but were not in the intervention population. RESULTS: The average number of CT scans per month for the high-exposure population decreased over time, but most of that reduction occurred 6-9 months before our interventions took place. At about the same time, the number of CT scans per month also decreased in adult Medicaid patients without cancer who had at least 1 CT scan but were not in the intervention population. LIMITATIONS: Our data do not include information about CT scans that may have been performed during times when patients were not covered by Medicaid. Some of our letters may not have been received or understood. Some high-exposure patients were unintentionally excluded from our study because organization of data on Medicaid claims varies by setting of care. CONCLUSION: Our patient education intervention was not temporally associated with significant decreases in subsequent CT exposure. Effecting behavior change to reduce exposure to ionizing radiation requires more than an educational letter or telephone call.