Off-label prescribing common, study shows

You're not the only one prescribing off-label, according to a study of Canadian primary care doctors. Find out how often it happens.

If you prescribe medications off-label, you’re not alone. A Canadian study of primary care physicians show the practice is quite common, according to results published in the Archives of Internal Medicine.

Researchers from McGill University in Montreal studied 113 primary care physicians who wrote 253,347 electronic prescriptions for 50,823 patients from January 2005 through December 2009.

Overall, 11% of medications were prescribed for an off-label indication, and 79% of off-label use lacked strong scientific evidence, the results indicate. The authors noted the magnitude of off-label use was less than in a 2006 U.S. study, which showed a rate of 21%.

Off-label prescribing varied by medication, patient, and physician characteristics, according to authors. The highest proportion of off-label prescribing involved central nervous system medications (26.3%), anti-infective agents (17.1%), and ear-nose-throat medications (15.2%), according to the results.

The results indicate that medications with three or four approved indications were associated with lower off-label use compared with those with one or two approved indications. Medications approved after 1995 also were associated with lower off-label use than those approved before 1981. Physicians with high scores on evidence-based methods were less likely to prescribe off-label.

“Our findings indicate that off-label prescribing is common in primary care and varies by drug class, the number of approved indications for the drug, the age of the drug, patients’ sex and physicians’ attitude toward evidence-based medicine,” the authors write. “Electronic health records can be used to document treatment indication at the time of prescribing and may pave the way for enhanced postmarketing evaluation of drugs if linked to treatment outcomes.”

In an accompanying editorial, Patrick G. O’Malley, MD, MPH, of the Uniformed Services University of the Health Sciences, Bethesda, Maryland, writes that physicians prescribe off-label occasionally when their patients’ conditions aren’t responding to available treatments.

“Here is my view about a way forward on this topic,” he writes. “First, the discourse needs to focus less on overuse or underuse or off-label use and more on evolving toward better measurement of use, better assessment of appropriate use based on linkage to clinical outcomes, and better processes to optimize use.”

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