EULAR recommendations for the management of psoriatic arthritis with pharmacological therapies: 2023 update.

OBJECTIVE: New modes of action and more data on the efficacy and safety of existing drugs in psoriatic arthritis (PsA) required an update of the EULAR 2019 recommendations for the pharmacological treatment of PsA. METHODS: Following EULAR standardised operating procedures, the process included a systematic literature review and a consensus meeting of 36 international experts in April 2023. Levels of evidence and grades of recommendations were determined. RESULTS: The updated recommendations comprise 7 overarching principles and 11 recommendations, and provide a treatment strategy for pharmacological therapies. Non-steroidal anti-inflammatory drugs should be used in monotherapy only for mild PsA and in the short term; oral glucocorticoids are not recommended. In patients with peripheral arthritis, rapid initiation of conventional synthetic disease-modifying antirheumatic drugs is recommended and methotrexate preferred. If the treatment target is not achieved with this strategy, a biological disease-modifying antirheumatic drug (bDMARD) should be initiated, without preference among modes of action. Relevant skin psoriasis should orient towards bDMARDs targeting interleukin (IL)-23p40, IL-23p19, IL-17A and IL-17A/F inhibitors. In case of predominant axial or entheseal disease, an algorithm is also proposed. Use of Janus kinase inhibitors is proposed primarily after bDMARD failure, taking relevant risk factors into account, or in case bDMARDs are not an appropriate choice. Inflammatory bowel disease and uveitis, if present, should influence drug choices, with monoclonal tumour necrosis factor inhibitors proposed. Drug switches and tapering in sustained remission are also addressed. CONCLUSION: These updated recommendations integrate all currently available drugs in a practical and progressive approach, which will be helpful in the pharmacological management of PsA.

Use of Coordinator Role Improves Access to Rheumatologic Advanced Therapy.

OBJECTIVE: Delays in initiation of advanced therapies, which include biologics and targeted synthetic disease-modifying antirheumatic drugs, contribute to poor patient outcomes. The objective of this quality improvement project was to identify factors that lead to a delay in the initiation of advanced therapy and to perform plan-do-study-act cycles to decrease the time to start advanced therapy. METHODS: A retrospective chart review identified factors involved in delay to start advanced therapy. The primary outcome of the study was the number of days to advanced therapy start as measured by the date of rheumatologist recommendation to the date advanced therapy was initiated by the patient. An Advanced Therapy Coordinator role was created to standardize the workflow, optimize communication, and ensure a safety checklist was instituted. RESULTS: A total of 125 patients were reviewed for the study with 18 excluded. Preintervention median wait time was 82.0 (IQR 46.0-80.5) days. Median wait time during the intervention improved to 49.5 (IQR 34.0-69.5) days (April 2021 to January 2022), with nonrandom variation post intervention. Nonrandom variation was also noted in the latter baseline data (March 2020 to March 2021). CONCLUSION: This study demonstrates improved wait time to advanced therapy initiation through the role of an Advanced Therapy Coordinator to facilitate communication pathways.

Using Ultrasound to Improve Diagnostic Confidence and Management of Psoriatic Disease: Highlights From the GRAPPA 2023 Ultrasound Workshop.

The sensitivity of ultrasound (US) to detect, characterize, and monitor the relevant pathologies of psoriatic arthritis (PsA), including synovitis, enthesitis, tenosynovitis, and dactylitis, has made it an attractive tool for informing clinical decisions. The Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) US working group ran 2 sessions during the annual GRAPPA meeting held in July 2023 in Dublin, Ireland. During the first workshop, the group presented 2 topics, followed by a live demonstration and a group discussion. The 2 topics were (1) an overview of the Diagnostic Ultrasound Enthesitis Tool (DUET) enthesitis scoring methodology, and (2) small hand-held probes-will the promise deliver? The live demonstration that followed compared the performance of 2 hand-held US (HHUS) devices vs a console US machine in patients with PsA, and the interactive group discussion considered gaps in the literature and future research suggestions relating to HHUS and its application in psoriatic disease. During the second session, the US working group provided further updates regarding the GRAPPA US studies currently underway or recently completed.

Insights and Innovations: A Review of the GRAPPA 2023 Trainee Symposium.

The Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) 2023 annual meeting started with the trainee symposium. This symposium showcased the exceptional research activities of dermatology and rheumatology trainees in the field of psoriatic diseases (PsDs). The following report is a summary account of the 5 oral presentations and 21 poster presentations that earned the privilege of being featured at our annual meeting. These presentations span a comprehensive spectrum, encompassing basic/translational, clinical, and outcomes research, which collectively underscore GRAPPA's profound impact on both national and international fronts in the realm of PsDs.

Sex-Related Differences in Dispensation of Rheumatic Medications in Older Patients With Inflammatory Arthritis: A Population-Based Study.

OBJECTIVE: The aim of our study was to compare dispensation of rheumatic medications between older male and female patients with early rheumatoid arthritis (RA) and psoriatic arthritis (PsA). METHODS: This retrospective cohort study was performed using health administrative data from Ontario, Canada (years 2010-2017), on patients with incident RA and PsA, who were aged ≥ 66 years at the time of diagnosis. Yearly dispensation of rheumatic drugs was compared between older male and female patients for 3 years after diagnosis using multivariable regression models, after adjusting for confounders. The groups of drugs included in the analysis were disease-modifying antirheumatic drugs (DMARDs) classified as conventional synthetic DMARDs (csDMARDs) and advanced therapy (biologic DMARDs and targeted synthetic DMARDs), nonsteroidal antiinflammatory drugs (NSAIDs), opioids, and oral corticosteroids. Results were reported as odds ratios (ORs) with 95% CIs. RESULTS: We analyzed 13,613 patients (64% female) with RA and 1116 patients (57% female) with PsA. Female patients with RA were more likely to receive opioids (OR 1.39, 95% CI 1.22-1.58 to OR 1.51, 95% CI 1.32-1.72) and NSAIDs (OR 1.14, 95% CI 1.04-1.25 to OR 1.16, 95% CI 1.04-1.30). Dispensation of DMARDs showed no sex difference in either group. Subgroup analyses showed more intense use of advanced therapy in the RA cohort and of csDMARDs in the PsA cohort when patient and physician sex was concordant. CONCLUSION: This study did not identify any sex difference in the use of DMARDs among older patients with RA and PsA. The reasons for the higher use of opioids and NSAIDs among female patients with RA warrant further research.

GRAPPA 2023 Collaborative Research Network Meeting.

The Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) Collaborative Research Network (CRN)/research committee met during the GRAPPA 2023 annual meeting. Updates were provided on GRAPPA research projects, including the Axial Involvement in Psoriatic Arthritis (AXIS), Axial Psoriatic Arthritis Molecular and Clinical Characterisation Study, Diagnostic Ultrasound Enthesitis Tool (DUET), and Sex- and Gender-Based Analysis of the Effectiveness of Advanced Therapies (SAGE) studies, as well as the Health Initiatives in Psoriasis and Psoriatic Arthritis Consortium European States (HIPPOCRATES) and Elucidating the Landscape of Immunoendotypes in Psoriatic Skin and Synovium (ELLIPSS) studies. The highlight of the meeting was a presentation and discussion on the use of digital tools to study psoriatic disease.

GRAPPA 2023: Major Projects, Key Advances, and Milestones.

At the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) 2023 annual meeting, members were updated on a number of ongoing activities during the key project update session. These activities included the Axial Involvement in Psoriatic Arthritis (AXIS) cohort, the Axial Psoriatic Arthritis Molecular and Clinical Characterization study, the Diagnostic Ultrasound Enthesitis Tool (DUET) study, the Sex- and Gender-Based Analysis of the Effectiveness of Advanced Therapies in Psoriatic Arthritis (SAGE-PsA) study, the Health Initiatives in Psoriasis and Psoriatic Arthritis Consortium European States (HIPPOCRATES), the GRAPPA slide library, and the GRAPPA treatment recommendations.

Canadian Rheumatology Association/Spondyloarthritis Research Consortium of Canada Living Treatment Recommendations for the Management of Axial Spondyloarthritis.

OBJECTIVE: To provide a set of living treatment recommendations that will provide contemporary guidance on the management of patients with axial spondyloarthritis (axSpA) in Canada. METHODS: The Spondyloarthritis Research Consortium of Canada (SPARCC), in conjunction with the Canadian Rheumatology Association, organized a treatment recommendations panel composed of rheumatologists, researchers, allied health professionals, and a patient advocate. A Grading of Recommendations Assessment, Development, and Evaluation (GRADE)-ADOLOPMENT approach was used in which existing guidelines were adopted or adapted to a Canadian context. Recommendations were also placed in a health equity framework. RESULTS: 56 recommendations were made for patients with active axSpA, stable axSpA, active or stable axSpA, comorbidities, and for assessment, screening, and imaging. Recommendations were also made for principles of management, disease monitoring, and ethical considerations. CONCLUSION: These living treatment recommendations will provide up to date guidance for the management of axSpA for Canadian practice. As part of the living model, they will be updated regularly as changes occur in the treatment landscape.

Residual Disease Activity in Canadian Patients With Psoriatic Arthritis Treated With Advanced Therapies: Results From a Multiregistry Analysis (UNISON-PsA).

OBJECTIVE: Although patient outcomes in psoriatic arthritis (PsA) have improved with the advent of advanced therapies, there remains a high unmet need to treat residual disease activity. The objective of the current study was to quantify residual disease activity and burden of disease in Canadian patients with PsA. METHODS: This was a multiregion, observational, retrospective analysis of patient data extracted from the Rhumadata and the International Psoriasis and Arthritis Research Team (IPART) registries, analyzing deidentified data from patients who had initiated advanced therapy for the treatment of PsA between January 2010 and December 2019. The primary endpoint was the proportion of patients failing to achieve minimal disease activity (MDA) within 6 months; secondary endpoints included clinical and patient-reported burden of disease. Descriptive statistics included summaries by region, treatment class, and number of prior advanced therapies. RESULTS: One thousand five hundred ninety-six patients were included. The proportions of patients who failed to achieve MDA within 6 months of an advanced therapy were 64.8% in Ontario, 68.3% in Western Canada, 74.8% in Quebec, and 75% in the Atlantic/East region. Failure to achieve MDA was higher among patients receiving an IL-17i compared with a TNFi in all regions except the Atlantic/East. Between 73.2% and 78.6% of patients reported pain at 6 months, and continuing functional impairment varied from 24% in the West to 83.3% in the Atlantic/East. CONCLUSION: There is substantial burden and unmet need for improved therapies for Canadians with PsA. There is a wide regional variation in outcomes that requires further assessment.

The impact of dietary interventions in psoriatic arthritis.

PURPOSE OF REVIEW: Psoriatic arthritis (PsA) is a common form of inflammatory arthritis that affects people with psoriasis. Both psoriasis and PsA are associated with metabolic diseases including obesity, hypertension, hyperlipidaemia, diabetes mellitus, fatty liver disease, and cardiovascular disease including myocardial infarction. Dietary interventions for psoriatic disease have been of great interest, particularly among patients with PsA. RECENT FINDINGS: Herein, we review the evidence for dietary intervention in psoriatic arthritis. To date, weight loss among patients who are obese has the greatest evidence for benefit. We also examine the evidence for fasting, nutrient supplementation, and specific diets as adjunct therapeutic strategies. SUMMARY: While the data do not clearly support a single dietary intervention across the disease, weight loss among those who are obese results in improved PsA disease activity and physical function. Additional studies are needed to better understand the impact of diet on psoriatic arthritis.

Understanding sex-related differences in healthcare utilisation among patients with inflammatory arthritis: a population-based study.

OBJECTIVES: Our aim was to compare patterns of musculoskeletal-related healthcare utilisation between male and female patients before and after the diagnosis of inflammatory arthritis (IA). METHODS: We used Ontario administrative health data to create three inception cohorts of adult patients with rheumatoid arthritis (RA), ankylosing spondylitis (AS) and psoriatic arthritis (PsA) diagnosed between April 2010 and March 2017. Healthcare utilisation indicators including visits to physicians, and use of musculoskeletal imaging and laboratory tests were assessed in each year for 3 years before and after diagnosis and compared between male and female patients using regression models adjusting for sociodemographic factors and comorbidities. Results were reported as ORs with 95% CIs for female patients compared with male patients. RESULTS: A total of 41 277 patients with RA (69% female), 8150 patients with AS (51% female) and 6446 patients with PsA (54% female) were analysed.Similar trends of sex-related differences were observed in all three cohorts. Before diagnosis, female patients were more likely to visit rheumatologists (OR 1.32-2.28) and family physicians (OR 1.03-1.15) for musculoskeletal reasons, whereas male patients were more likely to visit the emergency for musculoskeletal reasons (OR 0.76-0.87). A similar female predominance was observed regarding musculoskeletal imaging and laboratory tests before diagnosis. After diagnosis, female patients were more likely to remain in rheumatology care (OR 1.12-1.24). CONCLUSION: Female patients with IA have higher healthcare utilisation than male patients which may indicate biological differences in disease course or sociocultural differences in healthcare-seeking behaviour.

Defining imaging sub-phenotypes of psoriatic arthritis: integrative analysis of imaging data and gene expression in a PsA patient cohort.

OBJECTIVES: To define imaging sub-phenotypes in patients with PsA; determine their association with whole blood gene expression and identify biological pathways characterizing the sub-phenotypes. METHODS: Fifty-five patients with PsA ready to initiate treatment for active disease were prospectively recruited. We performed musculoskeletal ultrasound assessment of the extent of inflammation in the following domains: synovitis, peritenonitis, tenosynovitis and enthesitis. Peripheral whole blood was profiled with RNAseq, and gene expression data were obtained. First, unsupervised cluster analysis was performed to define imaging sub-phenotypes that reflected the predominant tissue involved. Subsequently, principal component analysis was used to determine the association between imaging-defined sub-phenotypes and peripheral blood gene expression profile. Pathway enrichment analysis was performed to identify underlying mechanisms that characterize individual sub-phenotypes. RESULTS: Cluster analysis revealed three imaging sub-phenotypes: (i) synovitis predominant [n = 31 (56%)]; (ii) enthesitis predominant [n = 13 (24%)]; (iii) peritenonitis predominant [n = 11 (20%)]. The peritenonitis-predominant sub-phenotype had the most severe clinical joint involvement, whereas the enthesitis-predominant sub-phenotype had the highest tender entheseal count. Unsupervised clustering of gene expression data identified three sub-phenotypes that partially overlapped with the imaging sub-phenotypes suggesting biological and clinical relevance of these sub-phenotypes. We therefore characterized enriched differential pathways, which included: immune system (innate system, B cells and neutrophil degranulation), complement system, platelet activation and coagulation function. CONCLUSIONS: We identified three sub-phenotypes based on the predominant tissue involved in patients with active PsA. Distinct biological pathways may underlie these imaging sub-phenotypes seen in PsA, suggesting their biological and clinical importance.

Ultrasound, magnetic resonance imaging and radiography of the finger joints in psoriatic arthritis patients.

OBJECTIVES: To report the discrepancies and agreements between US, MRI and radiography of the hand in PsA, and to compare the sensitivity and specificity of US and radiography to MRI as the gold standard imaging study in PsA. METHODS: All of the 100 prospectively recruited consecutive PsA patients underwent clinical assessment and concomitant radiographic, US and MRI studies of the MCP, PIP and DIP joints of one hand. Synovitis, flexor tenosynovitis, extensor paratenonitis, erosions and bone proliferations were identified and scored. All readers were blinded to clinical data, and agreement was calculated based on prevalence-adjusted bias-adjusted kappa (PABAK). RESULTS: The prevalence of synovitis, flexor tenosynovitis, extensor paratenonitis and erosions was similar for US and MRI, while that of bone proliferation was significantly increased in US and radiography compared with MRI (P < 0.001). The absolute agreement between US and MRI was good-to-very good for synovitis (85-96%, PABAK = 0.70-0.92), flexor tenosynovitis (93-98%, PABAK = 0.87-0.96) and extensor paratenonitis (95-98%, PABAK = 0.90-0.97). Agreement between US, MRI and radiography was 96-98% (PABAK = 0.92-0.97) for erosions and 71-93% (PABAK = 0.47-0.87) for bone proliferations. Sensitivity of US with MRI as gold standard was higher for synovitis (0.5-0.86) and extensor paratenonitis (0.63-0.85) than for flexor tenosynovitis (0.1-0.75), while the specificity was high for each pathology (0.89-0.98). CONCLUSION: There is very good agreement between US and MRI for the detection of inflammatory changes in finger joints in PsA. US, radiography and MRI have a good-to-very good agreement for destructive changes.

Targeted metabolomic profiling and prediction of cardiovascular events: a prospective study of patients with psoriatic arthritis and psoriasis.

OBJECTIVE: In patients with psoriatic disease (PsD), we sought serum metabolites associated with cardiovascular (CV) events and investigated whether they could improve CV risk prediction beyond traditional risk factors and the Framingham Risk Score (FRS). METHODS: Nuclear magnetic resonance metabolomics identified biomarkers for incident CV events in patients with PsD. The association of each metabolite with incident CV events was analysed using Cox proportional hazards regression models first adjusted for age and sex, and subsequently for traditional CV risk factors. Variable selection was performed using penalisation with boosting after adjusting for age and sex, and the FRS. RESULTS: Among 977 patients with PsD, 70 patients had incident CV events. In Cox regression models adjusted for CV risk factors, alanine, tyrosine, degree of unsaturation of fatty acids and high-density lipoprotein particles were associated with decreased CV risk. Glycoprotein acetyls, apolipoprotein B and cholesterol remnants were associated with increased CV risk. The age-adjusted and sex-adjusted expanded model with 13 metabolites significantly improved prediction of CV events beyond the model with age and sex alone, with an area under the receiver operator characteristic curve (AUC) of 79.9 versus 72.6, respectively (p=0.02). Compared with the FRS alone (AUC=73.9), the FRS-adjusted expanded model with 11 metabolites (AUC=75.0, p=0.72) did not improve CV risk discrimination. CONCLUSIONS: We identify novel metabolites associated with the development of CV events in patients with PsD. Further study of their underlying causal role may clarify important pathways leading to CV events in this population.

Role of ultrasound for assessment of psoriatic arthritis patients with fibromyalgia.

OBJECTIVE: To investigate whether ultrasonography (US), as an objective imaging modality, can optimise the evaluation of disease activity in psoriatic arthritis (PsA) patients with concomitant fibromyalgia syndrome (FMS). METHODS: The study population included 156 consecutive PsA patients who were recruited prospectively and fulfilled the ClASsification criteria for Psoriatic ARthritis criteria. The patients underwent complete clinical evaluation including assessment of fulfilment of the 2016 fibromyalgia classification criteria. All of the patients underwent US evaluation including 52 joints, 40 tendons and 14 entheses. The US score was based on the summation of a semiquantitative score (including synovitis, tenosynovitis and enthesitis). Scoring was performed by a sonographer blinded to the clinical data. Spearman's correlation coefficient and multivariate linear regression models were used to examine the association of FMS with clinical and the US scores. RESULTS: Forty-two patients (26.9%) with coexisting PsA and FMS were compared with 114 (73.1%) PsA patients without FMS. Patients with PsA and FMS had significantly increased scores for clinical composite indices, including non-Minimal Disease Activity, Composite Psoriatic Disease Activity Index (CPDAI), Disease Activity for Psoriatic Arthritis (DAPSA) and Psoriatic Arthritis Disease Activity Score (PASDAS) (p<0.001). In contrast, the total US score and its subcategories were similar for those with and without FMS. The total US score significantly correlated with CPDAI, DAPSA and PASDAS (p<0.001) in the PsA without FMS but not in the PsA with FMS group. FMS was significantly associated with higher clinical scores (p<0.001) but not with the US score (multivariable linear regression models). CONCLUSIONS: US has significantly greater value than composite clinical scores in the assessment of disease activity in PsA patients with FMS.

What influences patients' opinion of remission and low disease activity in psoriatic arthritis? Principal component analysis of an international study.

OBJECTIVE: In PsA, the treatment objective is remission or low disease activity (LDA), but patients' perception of remission is poorly studied. This analysis aimed to identify factors associated with patient-defined remission. METHODS: This analysis uses ReFlaP data, an international PsA study, with remission defined as 'At this time, is your psoriatic arthritis in remission, if this means: you feel your disease is as good as gone?'. Variables associated with, first, patient-defined remission and, second, LDA were identified using multivariable logistic regression and principal component analysis (PCA) to explore correlated variables. RESULTS: Of 424 patients (50.2% male, mean age 52 years) with established disease, 94 (22.2%) reported themselves as being in remission and 191 (45.0%) as LDA alone. In multivariable analysis pain, psoriasis, impact of disease, physician opinion of symptoms from joint damage and Groll comorbidity index were independent predictors of remission. For LDA, results were similar. Using PCA, variance explained was 74% by five components for men and 80% by six components for women. The key component from PCA for remission was, for both sex, disease impact (Psoriatic Arthritis Impact of Disease, pain and HAQ) explaining 22.2-27.5% of variance. Other factors included musculoskeletal disease activity, chronicity/joint damage, psoriasis, enthesitis and CRP. For LDA, similar factors were identified but the variance explained was lower (64-68%). CONCLUSION: Many factors impact on patients' opinion of remission, dominated by disease impact. Disease activity in multiple domains, chronicity/age, comorbidities and symptoms due to other conditions contribute to a robust model highlighting that patient-defined remission is multifaceted. TRIALS REGISTRATION: Clinicaltrials.gov, http://clinicaltrials.gov, NCT03119805.

Trends in mortality and cause-specific mortality among patients with psoriasis and psoriatic arthritis in Ontario, Canada.

BACKGROUND: There is limited information about mortality rates among patients with psoriasis and psoriatic arthritis (PsA) in North America and their change over the past 2 decades. OBJECTIVE: To compare all-cause and cause-specific mortality rates in patients with psoriasis to the general population in Ontario, Canada, from 1996 to 2016. METHODS: We conducted a population-based, retrospective cohort study of adult residents using administrative health data. All-cause and cause-specific standardized mortality rates, standardized mortality ratios, and excess mortality rates were calculated. RESULTS: 176,858 (2,524 deaths) patients with psoriasis and 15,430 (221 deaths) patients with PsA were identified in 2016. Patients with psoriasis and PsA had standardized excess mortality rates of 1.44 and 2.43 per 1000 population, respectively. Standardized mortality rates decreased by approximately 30% over the study period in both disease groups but remained significantly elevated compared to the general population. The leading causes of death in psoriasis and PsA patients were cancer, circulatory disease, and respiratory conditions. LIMITATIONS: We were unable to classify patients according to disease severity. CONCLUSIONS: Despite improvements in psoriasis treatment, the relative excess mortality, which may be related to risk factors for psoriatic disease, remained unchanged, with an average of approximately 1 to 2 extra deaths per 1,000 patients in 2016.

The Role of Ultrasound in Research and Clinical Practice in Psoriatic Arthritis: Highlights From the GRAPPA Ultrasound Workshop.

Ultrasound (US) is a valuable imaging modality that can accurately identify relevant features of psoriatic arthritis (PsA), such as synovitis, tenosynovitis, and enthesitis. The Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) Ultrasound Committee ran a workshop during the annual GRAPPA meeting that was held in July 2020. The group presented the following 3 topics: (1) the transition from psoriasis to PsA and the role of US; (2) the effect of biomechanical forces on the entheses in health and disease, and insight for PsA pathogenesis; and (3) differentiation of enthesitis from pain sensitization: use and limitations of clinical and sonographic evaluation of enthesitis. This article summarizes the key messages from this workshop.

Report of the Skin Research Working Groups From the GRAPPA 2020 Annual Meeting.

At the 2020 annual meeting of the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA), the International Dermatology Outcome Measures (IDEOM) Initiative Psoriasis (PsO) Working Group presented an update on its work to agree on meaningful, valid, and feasible outcome measures for PsO randomized controlled trials and longitudinal observational studies. The Treatment Satisfaction Working Group presented the development of a treatment satisfaction instrument to be utilized in PsO clinical trials. The Musculoskeletal Symptoms Working Group presented an overview of their work conducted to date to define how to best measure musculoskeletal symptoms in PsO clinical studies, and discussed next steps during an open-panel discussion, which included PsO and psoriatic arthritis experts.

Instruments Measuring Physical Function for Psoriatic Arthritis Endorsed at GRAPPA 2020 Annual Meeting: Updates of the GRAPPA-OMERACT Working Group.

The Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA)-Outcome Measures in Rheumatology (OMERACT) Psoriatic Arthritis (PsA) Working Group provided updates at the 2020 GRAPPA annual meeting on its work toward developing a core outcome set for PsA. Working groups were set up for the 4 prioritized domains: enthesitis, fatigue, structural damage, and physical function. Two instruments for measurement of physical function were provisionally endorsed: (1) the Health Assessment Questionnaire-Disability Index and (2) the physical functioning domain in the Medical Outcomes Study 36-item Short Form survey.