AJR: CT use rising among older fall victims

An analysis of CT utilization trends for fall victims admitted to a level I trauma center has shown a marked increase in CT use—particularly thoracic CT—and found an association between CT use and variables such as sex and age, according to a study published in the May issue of the American Journal of Roentgenology.

“The escalating use of imaging technology during the past two decades has raised serious concerns pertaining to the cost of care and patient safety,” wrote Bahman Roudsari, MD, PhD, and colleagues from the University of Washington in Seattle. They targeted their evaluation of CT use for fall victims to patients older than 55 years.

Using ICD-9-CM codes, the authors looked at trauma registry data between 1996 and 2006, and identified the type and frequency of CT exams, evaluating associations between utilization and other patient characteristics.

CT exams of the head, abdomen, thorax and other body regions increased an average of 7, 16, 14 and 15 percent, respectively, reported Roudsari et al. They noted that abdominal CT use did not significantly increase until 2002, when utilization jumped suddenly. Repeat CT scans of the head and abdomen also increased over the course of the study.

Age was not associated with the use of abdominal or thoracic CT, but it was associated with a higher use of head CT. “Traumatic brain injuries, including those due to acute and chronic subdural hematomas, are among the most vicious consequences of falls that might be missed in older adults with some level of dementia at baseline. Therefore, it is expected that physicians have a lower threshold for ordering head CT for older patients,” wrote the authors.

Another association--one that surprised the authors--was male sex being associated with higher utilization of all types of CT, even after adjusting for other covariates. This had not been shown in previous research. The authors speculated this could be due to the higher prevalence of comorbidities in older men compared with older women.

Neither insurance status nor ethnicity was significantly associated with CT use.

The authors addressed some limitations of the study, including the fact that during the study period, three significant changes occurred in the trauma center. PACS was established in 2003, and the following year, a CT scanner was installed in the ED. The hospital also converted from digital portable plates to a solid-state charge-couple device detector mount to the wall of the radiography room in the main ED. While all of these changes “significantly influence the availability and accessibility of imaging resources in our trauma center,” the authors wrote that with the data they had, they were not able to show that any of the changes was specifically associated with CT use.

They also blamed the limitations of ICD-9-CM codes for not being able to break “other CT” into subcategories such as lower extremity CT. “Because hip, femur, and pelvic fractures are the most common consequences of falls in older adults, it is conceivable that the availability of CT scanners and improvement in quality and speed of newer generation of scanners have contributed to the escalating trend in the use of ‘other CT’ in our study.”

The authors concluded by stressing that general trend analyses need to be complemented by other studies evaluating the association between utilization patterns and patient outcomes, especially for repeat CT exams.