Priority 7 from the Psoriatic Arthritis PSP

UNCERTAINTY: What is the best way to measure outcomes of treatment in psoriatic arthritis?  (JLA PSP Priority 7)
Overall ranking 7
JLA question ID 0108/7
Explanatory note This question aims to improve the way we measure the effect of treatment on psoriatic arthritis. Healthcare professionals can use outcomes like questionnaires and joint counts to monitor the response to ongoing therapies or the impact of changes to treatment plans.  For example, when attending follow-up appointments with healthcare professionals, can they accurately measure the effect of the treatment on a person’s lifestyle and symptoms? 
Evidence

This question has been partially addressed in the evidence base from the following systematic reviews:
Hojgaard, 2018. At least one patient reported outcome measure with some evidence for aspects of validity and reliability was available for six of the eight mandatory domains of the PsA core outcome set https://pubmed.ncbi.nlm.nih.gov/29037523/
Sacristan, 2020. In RA and PsA, studies were mainly focused on the evaluation of disease activity, which is perceived as higher from the patient's than the physician's perspective, with the discrepancy determined by factors such as patient's perception of pain and fatigue. Future research needed https://pubmed.ncbi.nlm.nih.gov/32555708/
Helliwell, 2019. A structured literature review suggested to improve disease monitoring a full disease assessment should be carried out annually and short term unscheduled appointments should be available within 2 weeks https://pubmed.ncbi.nlm.nih.gov/31154403/
Hagege, 2020. Remission (REM) or Low disease activity (LDA) can be used to monitor disease activity. The REM/LDA status was reported in only1/3 of recent studies on PsA, with important variations in the frequency of these outcomes according to the definition used: 13.1-42.1% for REM, and 36.3-60.4% for LDA. This highlights the need for consensus and further research https://pubmed.ncbi.nlm.nih.gov/32118267/
Cooper, 2018. Systematic review of quality measures for inflammatory arthritis including PsA. One set identified for PsA. Quality measures cover a diversity of themes encompassing process, structure, and outcomes of care across the 6 domains of quality. However, between organizations, measure development is not standardized. Local assessment of measurement feasibility before use outside the original development context is recommended https://pubmed.ncbi.nlm.nih.gov/29142026/
Machado, 2020. From this systematic review on measuring fatigue, none of the selected scales have had content validation, even though the FACIT was validated in patients with psoriatic arthritis. Validation studies in specific disorders are warranted https://pubmed.ncbi.nlm.nih.gov/33301180/
Health Research Classification System category Inflammatory and immune system
Extra information provided by this PSP
Original uncertainty examples Which is the best scoring system for psoriatic arthritis? 
Submitted by 8 uncertainties submitted 
PSP information
PSP unique ID 0108
PSP name Psoriatic Arthritis
Total number of uncertainties identified by this PSP. 46  (To see a full list of all uncertainties identified, please see the detailed spreadsheet held on the JLA website)
Date of priority setting workshop 12 July 2021