Students Research in Progress
Sunday, November 12, 2023
12:45 PM–02:15 PM
Abstract
Introduction: The narrow therapeutic range of warfarin requires frequent international normalized ratio (INR) monitoring and therapy adjustments to ensure patients are receiving a therapeutic warfarin dose. Many factors affect warfarin therapy, but tablet strength is one factor that has been less-well studied.
Research Question or Hypothesis: What is the relationship between warfarin tablet strength and time in therapeutic range (TTR) for patients taking warfarin at the University of Utah?
Study Design: Retrospective Cohort Study
Methods: Patients on warfarin with INRs tested between 06/01/2022 and 09/30/2022 were included in the study if they had history of at least 9 months of consistent warfarin use on the same tablet strength prior to study inclusion. TTR was calculated using linear interpolation for each patient during the 6-month period preceding their INR test during the reported study period. ANOVA and multiple variable regression tests were performed to evaluate the relationships between different warfarin tablet strengths and TTR.
Results: In total, 789 patients met the study eligibility criteria. Mean TTR for the entire cohort was 60.7% and standard deviation was 24.0%. TTR differences between warfarin tablet strength groups were not statistically significant (p-value = 0.235). Multivariable regression analysis and other tests are pending.
Conclusion: The results of this study are expected to suggest no significant relationship between different warfarin tablet strengths and TTR. Thus we recommend choosing a tablet strength that best supports patient adherence based on each individuals situation.
Presenting Author
Spencer Gilbert BSUniversity of Utah
Authors
Autumn Magill NA
University of Utah
Aubrey Jones PharmD, MSCI
University of Utah
Aaron Wilson PharmD
University of Utah College of Pharmacy
Daniel Witt PharmD
University of Utah College of Pharmacy