Design and Interpretation of Noninferiority Trials

Excerpt

Authors’ reply: We are grateful for the correspondents’ interest in our descriptive study of noninferiority trials.¹ Turgeon et al. have retrospectively extended the part of our analysis comparing ITT (intention-to-treat) and PP (per-protocol) methodologies to 2004. While we found that 64% of trials in our cohort from 2011 to 2016 reported both ITT and PP analyses, they found that only 45% of trials in the same journals between 2004 and 2014 reported both analyses. These results are consistent with those found in other reports, with modest increases over time in the reporting of both analyses.^2‐4 Regarding discordant results between analyses, both of our results reinforce the observation that the theoretical claim that PP analyses are more conservative than ITT analyses is empirically ungrounded. Ideally, both PP and ITT methodologies should be carefully described and reported with an a priori plan for handling discordant results when they occur. …