Abstract 254: Impact of Medical Study Publication on Cholesterol Medication Prescriptions

Abstract

Background: While research publication is associated with changes in clinical practice to varying degrees, it is unknown what spillover effects may change prescriptions of medications that are similar to, but different from, study medications. In 2008, the ENHANCE trial showed no benefit of simvastatin/ezetimibe over simvastatin alone, calling into question the benefit of ezetimibe. We hypothesize that this new ezetimibe information would have a negative impact by decreasing statin prescriptions. Methods: In the Source Healthcare Analytics ProMetis database, we performed a pre/post analysis of prescriptions rates for cholesterol-lowering medicines surrounding the January 14, 2008, release of the ENHANCE study results. We quantified prescription rates of the ENHANCE study medication simvastatin/ezetimibe, as well as ezetimibe alone and other cholesterol-lowering medications by class. This allowed us to assess the direct effect of the trial results on the affected drug, as well as potential spillovers to non-trial similar drugs. Results: From December 2007 to September 2008, simvastatin/ezetimibe prescriptions decreased nationally by averages of 70,594, 25,480, and 45,114 per month, for total, new, and refill prescriptions respectively. Ezetimibe total, new, and refill prescriptions decreased nationally by averages of 44,760, 16,141, and 28,618 per month, respectively. Conversely, total, new, and refill prescriptions for statins as a class increased by averages of 151,221, 43,599, and 107,621 per month, respectively. When examining the time immediately after the ENHANCE trial result release, simvastatin/ezetimibe and ezetimibe prescriptions decreased and at a steeper rate. Statin total, new, and refill prescriptions also decreased by 836,608, 208,114, and 628,494 from January to February 2008, respectively (Figure). Conclusions: These data suggest that the ENHANCE trial had spillover effects with a transient decrease in statin prescriptions. In light of the deleterious effects of acute statin discontinuation, this finding necessitates further exploration to understand the factors driving these health care decisions, and approaches to disseminating research findings that result in more targeted and appropriate changes in clinical practice.