Core outcome sets (COS)

Core outcome sets (COS)

What is a core outcome set?

A COS is a minimum set of outcomes of specific importance that should be measured and reported in all clinical trials for a specific condition. COS are developed with the input of relevant stakeholders, and patient engagement is a central part in the process of COS development.

Why use core outcome sets?

Clinical trials evaluate the safety and efficacy of interventions, treatments, or care procedures. To this end, one intervention is compared against an alternative intervention, for example placebo, in a trial. The effect of the intervention is seen as the difference between the groups when measuring different outcomes. It is crucial that these outcomes are of therapeutic importance to relevant stakeholders, such as patients and clinicians.

To provide the best clinical evidence, clinical trials within a field are systematically collected, assessed, and synthesized in systematic reviews. Often it is not possible to synthesize results of individual studies because different outcomes were measured. This, in turn, lowers the certainty of the evidence for the specific intervention.

As a producer of systematic reviews, SBU uses information from clinical trials. As such, SBU has been involved as a participant in the development of COS. SBU endorses the usage of robustly developed COS in clinical trials and in systematic reviews.

Useful links



SBU participation in development of COS




Transcription of manuscript for “SBU and core outcomes sets”