Are the correct outcomes being measured in studies of oral anticoagulants? A systematic survey.

INTRODUCTION

Oral anticoagulant (OAC) intervention trials have typically included clinical event outcomes. However, there is no standard list of outcomes to be used in OAC research. This study aimed to describe and classify the outcomes used in recent prospective clinical studies involving OACs.

MATERIALS AND METHODS

We searched MEDLINE, EMBASE, and CINAHL databases from January 2009 to July 2019 for prospective studies with an intervention or control group that included one or more oral anticoagulants. We abstracted details about each included study and the outcomes used from the study report and its accompanying protocol. Using the Core Outcome Measures in Effectiveness Trials (COMET) Initiative recommendations, we categorised each outcome into one of five domains (mortality/survival, physiological/clinical, life impact, resource use, and adverse events). Our primary outcome was the prevalence of use of an outcome domain across studies.

RESULTS

We included 70 prospective studies, including 52 randomized controlled trials and 18 prospective cohort studies. A total of 121 different outcomes were reported. The COMET domains were represented in the 70 studies as follows: mortality (63/70, 90.0%); physiological/clinical domain (70/70, 100%), life impact domain (43/70, 61.4%), resource use domain (26/70, 37.1%), and adverse events domain (55/70, 78.6%).

CONCLUSION

Outcome reporting in prospective studies of OACs more frequently concentrates on mortality, physiological/clinical domains, and adverse events compared to life impact and resource utilization domains, the latter uncommonly used. A priority for future research includes developing a core outcome set (COS) for OAC research that represents all domains.