Sample size
This nested trial was opportunistic in nature and statistical hypothesis testing should be viewed as exploratory. The sample size was determined by the number of participants in the Delphi study, which aimed to recruit 40 participants roughly balanced between patients and clinicians. Assuming a 15% loss to follow-up, this sample size allowed for two subpanels of 17 participants each (the rating and ranking study groups), which was equal to the median number of panelists found in a systematic review of Delphi studies published in healthcare [