Physician use of brand versus generic drug names in 1993-1994 and 2003-2004.

BACKGROUND: Physicians often refer to drugs by their brand names, which can result in brand name drugs being dispensed even when bioequivalent generic alternatives are available. As a result, use of brand-name terminology may result in increased drug costs.
OBJECTIVE: To evaluate how often physicians use brand and generic names of drugs, how the use of terminology changes over time, and factors associated with this change.
METHODS: This was a serial cross-sectional study using data from the National Ambulatory Medical Care Survey and the National Hospital Ambulatory Medical Care Survey in 1993/1994 and 2003/2004. Over the 4 study years, data were collected on 376,383 subjects. Using forms completed by physicians that described medication regimens, we determined the proportion of drug names that were recorded using brand vs nonproprietary (ie, generic) terminology.
RESULTS: In 1993/1994, the 25 most commonly mentioned drugs were referred to by their brand names a median of 89% of the time. Over the ensuing decade, use of brand-name terminology decreased by a median of 11%. Drugs that first faced generic competition within 10 years of the baseline study year had large declines in brand-name use (43-58% decline), whereas drugs that first faced generic competition more than 10 years before or after the baseline study year had minimal change in brand-name use (2-3% decline; p = 0.02 for difference in rate of decline among drug groups). Year of drug introduction, baseline rate of brand-name use, clinical setting, and national region were not associated with reductions in brand-name use.
CONCLUSIONS: Brand-name terminology is commonly used and decreases over time with the introduction of generic competition. Interventions that standardize medication-naming practices may hasten this decline and increase use of nonproprietary terminology in medicine.