Main issues emerging from breakout groups in establishing face, content, and construct validity requiring clarification and resolution for Filter 2.0.
| General issues | Are the criteria the same for each domain within instruments that cross domains? When and how to involve patients (especially in face and content)? When and how to involve others in addition to patients, clinicians, researchers, and approval agencies — e.g., general public, policy makers, economists, the press |
| Process issues | Can one get some Core Domain Instruments approved before others? E.g., Does core set development come to a stop if 1 or more Core Domains does not have a validated instrument? There should be provision for updating or revision of Core Outcome sets as further data accumulate |
| Face validity | How many of each group need to assess this? |
| Content validity | Should we always match subdomains and /or link to the ICF as external framework for “what to measure”? |
| Construct validity | Should there be a standard set of constructs? |
ICF: International Classification of Functioning, Disability and Health.