Box 2.

: Details that could be included in a trial register (least controversial items listed first)

• Title of trial
• Research question
• Study population and interventions
• Lead investigator or institution
• Funding organisation
• Unique identifier to prevent repeat registrations
• Status of trial—Ongoing or completed? Is trial still open to accrual? Contact address for potential participants
• Other details of methodology—Design, power calculation, outcomes, analysis
• Ethical aspects—Type of consent, information given to participants, approval by ethics committee
• Results—Published or unpublished? Abstracts presented? References to best account of results
• Full protocol