Received: 10 December 2020
Accepted: 27 August 2021
First Online: 6 September 2021
: Ethics approval was not required for this study as no data in human subjects was collected.
: Consent for publication was not required for this study as no data in human subjects was collected.
: CB Terwee and D Cella are members of the board of directors of the PROMIS Health Organization. CB Terwee, L Haverman and LD Roorda are representatives of the Dutch-Flemish PROMIS National Center. HE Vonkeman was part of the working group which developed the ICHOM Standard Set for inflammatory arthritis.