Table 1 Ten steps of the project including intermediate goals (in bold) and the team involved

Part 1

1

Discussion with and approval of the protocol by steering committee and methodological collaborators [e.g. COSMIN, C3 (CHORD/COUSIN Collaboration)]

SC, M, ST

2

Definition of scope and applicability for each setting

SC

3

Information, selection, and invitation of participant [including advisory panels/patient (focus) groups]: e.g., health care professionals/researchers, patients, industry representatives and subsequent comprehensive explanation of the protocol to participants

SC, M

4

Development provisional lists for outcome domains/domain items and contextual factors by steering committee and advisory panel based on preparative exercise: revision previous (2015) core domains for trials; definitions (patient focus groups/patient surveys), literature search + items used in existing clinical practice/registries + expert/patient opinions.

SC, PFG, AP

5

Electronic surveys according to e-Delphi technique to score the importance of outcome domain items and contextual factors (maximum 3 rounds) by all participants.

APT

6

A conclusive meeting will be organized to solve remaining disagreements or items with “no consensus.”

APT

7

Process (steps 4–6) will be repeated for each setting to construct 3 core domain sets (clinical trials; registries; clinical practice)

APT

Part 2

8

Quality assessment (evaluation of measurement properties) of available instruments for vitiligo (PROMs, ClinROM, and imaging techniques) by COSMIN checklist (updated systematic review).

CG

9

Selection of measurement instruments and measurement details (e.g., scale and timing) during consensus meetings guided by HOME and COSMIN recommendations for each setting.

APT

10

A final meeting will be organized to present an overview of the composed 3 dataset and to define the dissemination plan and implementation goals.

APT