Outpatient MRIs of the lumbar spine and of the head for headache are often targeted as indications where appropriateness should be more closely scrutinized, and an analysis of usage at two Canadian hospitals has shown that, in the case of lumbar spine MRI at least, this skepticism is warranted.

In a research letter published online March 25 in JAMA Internal Medicine, Derek J. Emery, MD, of the University of Alberta, and colleagues examined the appropriateness of outpatient lumbar spine and head MRIs at University of Alberta Hospital and Ottawa Hospital. While most MRIs of the head for headache were considered appropriate, they found less than half of lumbar spine MRIs were rated as such.

“Our study has implications for management of MRI usage for the lumbar spine, which makes up approximately a third of all MRI in some regions,” wrote the authors. “Eliminating inappropriate scans and some of uncertain value could reduce the harm that accrues from unneeded investigations and result in significant cost savings.”

Data were collected from University of Alberta Hospital from May 2008 to September 2009 and from the Ottawa Hospital from September 2008 to March 2010. A total of 500 lumbar spine MRI requisitions and 500 head MRI for headache requisitions from each hospital were evaluated by a pair of expert panels.

Only 443 of 1,000 lumbar spine MRI requests were considered appropriate, with the remaining split between inappropriate (28.5 percent) or of uncertain value (27.2 percent). Family physicians had a lower rate of appropriate MRI ordering for the low back than other specialties, according to Emery and colleagues.

MRI scans requested for headache were appropriate in 82.8 percent of cases, though since this was not a population-based study, the authors cautioned against extrapolating the results outside of the two hospitals studied. Most of the patients in the study were prescreened with a CT scan before being referred for MRI, which likely led to a higher rate of appropriate head MRIs, explained Emery and colleagues. The appropriateness of these CT scans was not assessed.

“Overuse of medical interventions, such as MRI, is a considerable problem, leading to excess costs and adverse outcomes,” wrote the authors. “Overuse is driven by many factors, including patient expectations, physician concerns about litigation and lack of physician accountability for cost. Solutions will require strict adherence to appropriate guidelines and better education of patients. The efforts of the Choosing Wisely consortium to mobilize medical societies to show leadership in reducing overuse is a positive step to this end.”

For more information on the Choosing Wisely campaign, click here.