Background: End points and adverse events (AEs) are collected separately in clinical trials, yet regulatory requirements for serious AE reporting vary across regions, so classifying end points according to seriousness criteria can be useful in global trials.
Methods and results: In the Apixaban for Prevention of Acute Ischemic Events 2 (APPRAISE-2) trial, patients with a recent acute coronary syndrome were randomized to apixaban or placebo for the prevention of recurrent ischemic events. Suspected end points (myocardial infarction, stroke, or bleeding) were adjudicated by an independent clinical events classification committee. Safety criteria were collected for suspected end points and AEs. Patient-level event rates per 100 patient-days of follow-up, modeled using Poisson regression, explored the influence of region and patient characteristics on event reporting. Overall, 13 909 events were reported by 858 sites in 39 countries; 8.4% (n=1166) were suspected end points, and 91.6% (n=12 743) were AEs. Overall, 66.0% of suspected end points were confirmed by the clinical events classification committee. Most clinical events classification committee-confirmed end points met criteria to be classified as serious (94.0%); many clinical events classification committee-negated end points also did (63.2%), but fewer AEs met seriousness criteria (17.9%). The most common seriousness criterion was hospitalization (79.9%, n=2594). Region explained 28.7% of end point- and 26.4% of serious AE-reporting variation, and patient characteristics explained an additional 25.4% of end point and 13.4% of serious AE variation. Nonserious AE-reporting variation was not explained by adjustment.
Conclusions: An integrated collection of end points and serious AEs is feasible in a multinational trial and illustrates the shared characteristics of events. Tailoring event collection to fit the phase and purpose of the trial is achievable and informative.
Clinical trial registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00831441.
Keywords: acute coronary syndrome; clinical end points; clinical events classification; safety; serious adverse events.
© 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.