Question # 39 A group of investigators conducted a randomized controlled trial to compare the effectiveness of rivaroxaban to warfarin for ischemic stroke prevention in patients with atrial fibrillation. A total of 14,000 participants were enrolled and one half was assigned to each of the cohorts. The patients were followed prospectively for 3 years. At the conclusion of the trial, the incidence of ischemic stroke in participants taking rivaroxaban was 1.7% compared to 2.2% in participants taking warfarin. The hazard ratio is calculated as 0.79 and the 95% confidence interval is reported as 0.64 to 0.97. If the study was conducted with a total of 7,000 participants, which of the following changes would most be expected? Answer A Increased risk of selection bias B Decreased hazard ratio C Increased confidence interval range D Decreased type I error rate E Increased risk of confounding bias F Decreased type II error rate Image