LAUSR

OBJECTIVE To assess the impact of narrative review (NR) versus systematic review (SR) on expert assessments of a clinical trial. STUDY DESIGN AND SETTING Experts in colon and rectal surgery were randomized to read a NR or SR for an ongoing clinical trial involving surgery for colorectal cancer. Experts from the US and Canada completed online or paper surveys between December 2018 to June 2019. After reading the NR or SR, experts predicted the trial's outcome and evaluated the trial under a hypothetical ethical review. RESULTS Experts who read the NR (n = 55) compared to those who read the SR (n = 56) were more likely to predict a higher absolute risk reduction, 58% vs 33%, p = 0.018, mean predictions 10.6% vs 6.6%, mean difference 4.0% [95% CI: 0.3%, 7.8%]. Experts who read the NR were more likely to evaluate the trial more favorably under a hypothetical ethical review, 48% vs 26%, p = 0.039, 20.0% vs 8.9% "Strongly in favor" of trial being pursued. CONCLUSIONS A NR and a SR for the same trial led to different judgments of likely outcomes and ethical appropriateness. These differences point to a potential source of unaddressed bias in ethical review.