Standardising outcome reporting for clinical trials of interventions for heavy menstrual bleeding: Development of a core outcome set

Objective
To develop a core outcome set for heavy menstrual bleeding (HMB).

Design
Core outcome set (COS) development methodology described by the COMET initiative.

Setting
University hospital gynaecology department, online international survey and web-based international consensus meetings.

Population or sample
An international collaboration of stakeholders (clinicians, patients, academics, guideline developers) from 20 countries and 6 continents.

Methods
Phase 1: Systematic review of previously reported outcomes to identify potential core outcomes. Phase 2: Qualitative studies with patients to identify outcomes most important to them. Phase 3: Online two-round Delphi survey to achieve consensus about which outcomes are most important. Phase 4: A consensus meeting to finalise the COS.

Main outcome measures
Outcome importance was assessed in the Delphi survey on a 9-point scale.

Results
From the ‘long list’ of 114, 10 outcomes were included in the final COS: subjective blood loss; flooding; menstrual cycle metrics; severity of dysmenorrhoea; number of days with dysmenorrhoea; quality of life; adverse events; patient satisfaction; number of patients going on to have further treatment for HMB and haemoglobin level.

Conclusions
The final COS includes variables that are feasible for use in clinical trials in all resource settings and apply to all known underlying causes of the symptom of HMB. These outcomes should be reported in all future trials of interventions, their systematic reviews, and clinical guidelines to underpin policy.