Characterizing the relationship between free drug samples and prescription patterns for acne vulgaris and rosacea

Abstract

Importance: Describing the relationship between the availability of free prescription drug samples and dermatologists' prescribing patterns on a national scale can help inform policy guidelines on the use of free samples in a physician's office.

Objectives: To investigate the relationships between free drug samples and dermatologists' local and national prescribing patterns and between the availability of free drug samples and prescription costs.

Design, setting, and participants: Cross-sectional study investigating prescribing practices for acne, a common dermatologic condition for which free samples are often available. The settings were, first, the offices of nationally representative dermatologists from the National Disease and Therapeutic Index (an IMS Health Incorporated database) and, second, an academic medical center clinic without samples. Participants were ambulatory patients who received a prescription from a dermatologist for a primary initial diagnosis of acne vulgaris or rosacea in 2010.

Main outcomes and measures: National trends in dermatologist prescribing patterns, the degree of correlation between the availability of free samples and the prescribing of brand-name medications, and the mean cost of acne medications prescribed per office visit nationally and at an academic medical center without samples.

Results: On a national level, the provision of samples with a prescription by dermatologists has been increasing over time, and this increase is correlated (r = 0.92) with the use of the branded generic drugs promoted by these samples. Branded and branded generic drugs comprised most of the prescriptions written nationally (79%), while they represented only 17% at an academic medical center clinic without samples. Because of the increased use of branded and branded generic drugs, the national mean total retail cost of prescriptions at an office visit for acne was conservatively estimated to be 2 times higher (approximately $465 nationally vs $200 at an academic medical center without samples).

Conclusions and relevance: Free drug samples can alter the prescribing habits of physicians away from the use of less expensive generic medications. The benefits of free samples in dermatology must be weighed against potential negative effects on prescribing behavior and prescription costs.

Figure 1

Trend in the percentage of prescriptions written with a sample by dermatologists compared to physicians in other medical specialties on a nationally projected basis. “Other” specialties correspond to allergy, cardiology, surgery, endocrinology, family practice, general practice, gastroenterology, geriatrics, hematology, internal medicine, nephrology, neurology, obstetrics/gynecology, oncology, ophthalmology, pediatrics, psychiatry, pulmonary diseases, rheumatology, and urology. (Source: IMS National Disease and Therapeutic Index^™ January, 2001 – December, 2010, IMS Health Incorporated. All Rights Reserved.)

Figure 2

The percent of prescriptions written with a sample and the percent of branded generic drugs as prescribed by office-based dermatologists for patients with acne vulgaris and acne rosacea on a nationally projected basis. (Source: IMS National Disease and Therapeutic Index^™ January, 2001 – December, 2010, IMS Health Incorporated. All Rights Reserved.)

Figure 3

Percentage of all branded, branded generic, and generic medications for acne vulgaris and rosacea prescribed during a patient’s initial visit in 2010 at an academic medical center (AMC) and on a nationally projected basis. Analyses are restricted to prescriptions written more than 3 times in 2010 at the AMC. (Source: STRIDE and IMS National Disease and Therapeutic Index^™ January, 2010 – December, 2010, IMS Health Incorporated. All Rights Reserved.)