LAUSR

Abstract Objectives To assess the degree to which removal of FDA’ Pregnancy Categories (PC) of medications (A, B, C, and D) from labeling, affects the likelihood that providers will prescribe those medications. Methods Over a one-year period a convenience sample of providers was recruited into a randomized, survey-based, study. Two versions of the survey were randomly distributed; version 1 presented clinical vignettes, drug information, and PC, while version 2, presented the identical information without the PC. Respondents were asked to estimate their likelihood of prescribing the drug. A mixed linear model was constructed, with likelihood of prescription as the dependent variable, treated as interval-scaled. Results Out of 169 surveys given out, 162 (96%) were returned. Simple effects analysis showed that the presence of PC letter significantly affected the decision to prescribe category B (p<0.001) and C drugs (p=0.008) but not the A or D. Participants were significantly less likely to prescribe class B and C drugs when the letters were not available for review. These findings remained significant even when controlling for covariates (p=0.001). Conclusions When a PC letter is absent on labeling, physicians were less likely to use category B and C drugs, the most common medications prescribed in pregnancy.