UCSF

Importance

As prescription drug costs rise, it is important to understand attitudes among primary care physicians and nurse practitioners (NPs) towards generic drugs.

Objective

We aimed to examine the generic skepticism index (GSI) among primary care clinicians, and their willingness to discuss and prescribe generic antidepressants (ADs) and generic oral contraceptives (OCPs).

Design

We used a factorial vignette design survey to test 4 factors: message source, message, brand preference, and drug class. Participants were randomized to different combinations of factors.

Setting

This was a cross-sectional study.

Participants

Physicians registered with the American College of Physicians (ACP) and NPs registered with the American Association of Nurse Practitioners (AANP) participated in the study.

Main measures

The primary outcomes were generic skepticism as measured using the generic skepticism index (GSI), and clinician willingness to discuss and prescribe generics.

Results

Surveys were completed by 56% of physicians (n = 369/661) and 60% of NPs (n = 493/819). Compared with physicians, NPs were younger (p < 0.001), predominantly female (p < 0.001), and differed in the race (p < 0.001). According to the GSI, 16% (n = 138/862) were identified as generic skeptics (18.5% of NPs and 12.7% of physicians, p = 0.023). Generic skeptics had lower odds of willingness to discuss switching (OR 0.22, 95% CI (0.14-0.35), p < 0.001) or prescribe (OR 0.18, 95% CI (0.11-0.28), p < 0.001) generic OCPs. Participants had lower odds of willingness to prescribe generic drugs to patients with brand preference compared with brand-neutral patients (OR 0.64, 95% CI 0.50-0.82, p < 0.001).

Conclusions and relevance

Generic skepticism was associated with lower willingness to discuss or prescribe generic drugs. Clinicians reported lower willingness to discuss switching or prescribe generics for OCPs than for ADs. Patient brand preference hindered generic prescribing. Message source and message type were not significantly associated with outcomes.