Table 1 Developing the COS process based on the COMET COS-STAD

Scope specification

1

The research or practice setting for the COS

Research and clinical practice

2

The health condition covered by the COS

Cancer

3

The population covered by the COS

AYAs aged 13–39 years at initial cancer diagnosis and inclusive of the whole cancer care continuum

4

The interventions covered by the COS

All

Stakeholders involved

5

Those who will use the COS in research

Researchers, policy-makers dealing with AYAs

6

Healthcare professionals with experience of patients with the condition

Clinicians (e.g. medical oncologists), nurse specialists, applied healthcare professionals

7

Patients with the condition or their representatives

Adolescents and young adults aged 13–39 years at first cancer diagnosis, their informal caregivers or advocates

Consensus process

8

Long-list of outcomes considered by stakeholders

Literature review and interviews with stakeholders

9

Scoring process and consensus definition

Delphi scoring using a nine-point Likert scale (1–3, limited importance; 4–6, not crucial importance; 7–9, crucial importance)

Consensus criteria: score of 7 + per item by ≥ 70% of respondents

10

Criteria for including/eliminating outcomes

Inclusion: outcomes scored ‘critically important’ by ≥ 70% AND ‘not important’ by < 15% of participants

Exclusion: outcomes scored ‘critically important’ from less than 50% of participants

11

Avoiding language ambiguity in the description of outcomes

Plain language version will be available, informed by interviews and pilot-tested with patients