Figure 1From: Predictors of warfarin use in atrial fibrillation in the United States: a systematic review and meta-analysis Result of a Linear Regression Analysis Evaluating the Correlation Between Warfarin Use Over Progressing Time. Dotted lines represent timing of seminal warfarin publications (Hylek 1996 and 2001 Update of the AHA/ACC Atrial Fibrillation Guidelines) [42, 44]. As studies were plotted on the horizontal axis based upon the first year of patient inclusion, data on warfarin use prior to 1996 is depicted. r = Pearson's correlation coefficient.Back to article page