Domains adjusted for cross-cultural DIF
| AS | PsA | SSc | SLE | FMS | |
|---|---|---|---|---|---|
| Pain | X | X | S | S | S |
| Movements | S | S | S | X | S |
| Feelings | S | S | S | S | S |
| Disease process | S | X | S | S | S |
| Treatments | S | X | X | X | S |
| Self-help | S | X | S | S | S |
| Support | X | X | X | S | S |
AS, ankylosing spondylitis; DIF, differential item functioning; FMS, fibromyalgia syndrome; PsA, psoriatic arthritis; S, cross-cultural invariance satisfied; SLE, systemic lupus erythematosus; SSc, systemic sclerosis; X, lack of cross-cultural invariance.