The funding sources had no role in the design and conduct of the study, analysis or interpretation of the data; and preparation or final approval of the manuscript prior to publication. The views expressed are the authors' and the article should not be construed as representing policies of the American Medical Association or any of the other organizations with which the authors are affiliated.
U.S. physician knowledge of the FDA-approved indications and evidence base for commonly prescribed drugs: results of a national survey†
Version of Record online: 14 AUG 2009
Copyright © 2009 John Wiley & Sons, Ltd.
Pharmacoepidemiology and Drug Safety
Volume 18, Issue 11, pages 1094–1100, November 2009
How to Cite
Chen, D. T., Wynia, M. K., Moloney, R. M. and Alexander, G. C. (2009), U.S. physician knowledge of the FDA-approved indications and evidence base for commonly prescribed drugs: results of a national survey. Pharmacoepidem. Drug Safe., 18: 1094–1100. doi: 10.1002/pds.1825
- Issue online: 22 OCT 2009
- Version of Record online: 14 AUG 2009
- Manuscript Accepted: 8 JUL 2009
- Manuscript Revised: 5 JUN 2009
- Manuscript Received: 23 DEC 2008
- FDA approval;
- off-label prescribing;
- drug regulation;
- FDA label;
- physician knowledge
The Food and Drug Administration (FDA) regulates prescription drug marketing, not prescribing. However, off-label use is common, often lacks supporting evidence, and may expose patients to unwarranted risk. We sought to determine physicians' knowledge of the FDA-approved indications of commonly prescribed drugs, and to assess whether physicians' belief that an indication is FDA-approved increases with level of evidence supporting such use.
We conducted a national random sample mail survey of 599 primary care physicians and 600 psychiatrists from November 2007 to August 2008. Physicians were presented with 14 drug-indication pairs (e.g., gabapentin [Neurontin®] for diabetic neuropathy) that varied in their FDA-approval status and levels of supporting evidence.
The adjusted response rate was 47%, respondents were similar to non-respondents, and physicians commonly prescribed the drugs examined. The average respondent accurately identified the FDA-approval status of just over half of the drug-indication pairs queried (mean 55%; median 57%). Accuracy increased modestly (mean 60%, median 63%) when limited to drugs the respondent reported having prescribed during the previous 12 months. There was a strong association between physicians' belief that an indication was FDA-approved and greater evidence supporting efficacy for that use (Spearman's ρ 0.74, p < 0.001). However, 41% of physicians believed at least one drug-indication pair with uncertain or no supporting evidence (e.g., quetiapine [Seroquel®] for dementia with agitation) was FDA approved.
These findings highlight a pressing need for more effective methods to inform physicians about the evidence base, or lack thereof, for drugs they prescribe off label. Copyright © 2009 John Wiley & Sons, Ltd.