In both axSpA and PsA, the relevant scores used to assess treatment success and to guide therapeutic decisions are either informed by patient reported outcome measures (PROMs), such as the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) or Bath Ankylosing Spondylitis Functional Index (BASFI) for axSpA or are composite scores containing PROMs (Ankylosing Spondylitis Disease Activity Score c-reactive protein (ASDAS-CRP) for axSpA and Disease Activity in Psoriatic Arthritis (DAPSA) for PsA). This evidence concerns the gene CRP and psoriatic arthritis.