Table 2 Proposed CMS development process based on COSMIN / COMET recommendations

Step 1. Conceptual considerations

• Target population: adolescents and young adults with cancer (AYAs)

• Intervention: all

• Outcomes: All outcomes included in the COS developed in previous phase

Step 2. (a) Identify existing outcome measurement instruments & (b) measurement properties

Outcome measurement instruments used in the literature will be identified as part of the literature review in step 1. When specific international recommendations exist for a certain measure, we will follow these. Specific attention will be paid to the language availability of measures

Step 3. Quality assessment of outcome measurement instruments

• Search for available reviews of evidence for the psychometric properties of each instrument

• If possible, a review will be undertaken for instruments where no previous reviews are available

Step 4. Selection of outcome measurement instruments for the COS

A table of the evidence of the psychometric properties with the AYA population and quality for each OMI will be prepared

Step 5. Stakeholder’s meeting

Stakeholder’s meeting to approve instruments selection based on the review results