Rate of CTs of Spine Continue to Grow as Overall Use Slows

The rate of CT study performance overall has slowed, but use of spine CT continues to escalate, according to a study published in the Journal of the American College of Roentgenology.

Researchers from France and the U.S. examined trends diagnostic CT use, looking specifically for trends over an 11-year period based on patient age and anatomical region (head/neck, abdomen/pelvis, chest, and spine).

Using records from a large, mostly fee-for-service insurance claims database, the researchers identified the CT procedures performed from 2000 to 2011. From a total of 35.6 million scans,97 percent were of the major body regions of interest. Of the total scans, 32.6 percent were of the head or neck, 38.6 percent of the abdomen or pelvis, 21.1 percent of the chest, and 4.8 percent of the spine.

The results showed that while the rates of diagnostic CT did increase substantially during that time period, the changes varied considerably according to age group and anatomical region. Those over 65 saw the largest increase in scans used with 72 percent for males and 87 percent for females. Younger adults, aged 18 to 24, saw between a 135 percent and 129 percent increase in use of diagnostic CT from 2000 to 2011.

The researchers reported that for the last two years of the study, 2009 to 2011, most age groups showed a modest to substantial decrease in use of diagnostic CT.

“As [other studies] have shown, there has been a notable increase in use of diagnostic CT from 2000 to 2011. However, from 2009 to 2011, diagnostic CT studies of the chest, abdomen/pelvis, and head/neck have leveled off or decreased, whereas CTs of the spine show a continued increase in many groups,” the authors wrote.

Head and neck diagnostic CT scans increased modestly in 2000, but the greatest relative change was among males aged 18 to 24 with an 88 percent increase from 2000 to 2011. There was a reduction across all age groups from 2009 to 2011, except for people over age 65:

• Females under 1: 21 percent reduction
• Males under 1: 25 percent reduction
• Females 55 to 64: 6 percent reduction
• Males 55 to 64: 3 percent reduction
• Females 65 or older: 2 percent increase
• Males 65 or older: 3 percent increase

There were varying levels of change for diagnostic abdominal and pelvic CT scans:

• Males 18 to 24: 197 percent increase
• Females 18 to 24 : 240 percent increase
• Females 10 to 17: 154 percent increase
• Males 25 to 34: 146 percent increase
• Females 25 to 34: 180 percent increase
• Males 35 to 44: 136 percent increase
• Females 35 to 44: 136 percent increase
• Males under 1: 14 percent decrease
• Females under 1: 41 percent decrease

Diagnostic chest CT use has increased more among females than males since 2000, particularly from 2003 to 2009.

• Females 18 to 24: 283 percent increase
• Males 18 to 24: 161 percent increase
• Females 25 and 30: 217 percent increase
• Males 25 to 34: 108 percent increase
• Females under 1: 367 percent increase
• Males under 1: 66 percent increase.

Finally, spine CTs, which made up about 5 percent of the total scans, increased substantially. For example:

• Males 18 to 24: 321 percent increase
• Females 18 to 24: 339 percent increase

The authors concluded that the increase in the rate of overall CT examinations slowed, but the use of spine CT studies continued to escalate. “Future research should consider whether the increase in use of spine CT leads to a benefit that outweighs the risk associated with the increased population-level cancer risk,” they wrote.