Abstract 16923: The Impact of the Publication of Cardiovascular Safety Signals on the Prescribing of Varenicline: an Interrupted Time-Series Analysis
Introduction: Concerns regarding the cardiovascular safety of varenicline, a smoking cessation drug, arose following the publication of a meta-analysis of randomized controlled trials in July 2011. The impact of this safety signal on the prescribing patterns of varenicline remains unknown.
Hypothesis: Our hypothesis was that the reported increased risk of adverse cardiovascular events resulted in a decreased prescription rate of varenicline.
Methods: This study was conducted using the Clinical Practice Research Datalink, a large primary care database from the United Kingdom (UK). An interrupted time-series analysis using segmented auto-regression was conducted to compare varenicline prescribing patterns in the pre-publication (January 2007-June 2011) and post-publication (July 2011-December 2012) study periods. The fitted model was used to estimate the predicted rate that would have been observed in the post-publication period in the absence of the published safety signal.
Results: In the pre-publication period, the estimated prescription rate of varenicline increased by 27.4 (95% CI = 17.0, 37.7) prescriptions per month per 100,000 person-years (PYs), resulting in a rate of 2,464 prescriptions per 100,000 PYs in June 2011. The safety signal resulted in an estimated drop in the prescription rate of 513.4 (95% CI = -1020.9, -5.9) prescriptions per 100,000 PYs, representing a 21% decrease in the estimated prescription rate (R2 = 0.82). In the post-publication period, there was a change in direction in the trend, with the prescription rate decreasing by 42.4 prescriptions per month per 100,000 PYs (95% CI = -92.9, 8.1) during this period. The differences between the observed and predicted rates are shown in the Figure.
Conclusions: The publication of the meta-analysis suggesting an increased risk of adverse cardiovascular events associated with its use resulted in a significant decrease in the prescription rate of varenicline in the UK.
Author Disclosures: K.B. Filion: None. M. Eberg: None. L. Azoulay: None.
- © 2014 by American Heart Association, Inc.