Total Hip Arthroplasty Versus Education and Exercise: A Propensity-Matched Analysis of 266 Patients Who Have Hip Osteoarthritis.

BACKGROUND: Total hip arthroplasty (THA) for osteoarthritis (OA) is a major health system cost. Education and exercise (Edu+Ex) programs may reduce the number of THAs needed, but supporting data is limited. This study aimed to estimate the treatment effect of THA versus Edu+Ex on pain, function, and quality of life outcomes 3- and 12-months after treatment initiation for hip OA. METHODS: Patients who had hip OA who underwent THA or an Edu+Ex program were included in this propensity-matched study. In 778 patients (Edu+Ex n = 303; THA n = 475), propensity scores were based on pre-treatment characteristics, and patients were matched on a 1:1 ratio. Between-group treatment effects (pain, function, and quality of life) were estimated as the mean difference in change from pre-treatment to 3- and 12-month follow-up using linear mixed models. RESULTS: The matched sample consisted of 266 patients (Edu+Ex n = 133; THA n = 133) that were balanced on all pre-treatment characteristics except opioid use. At 12-month follow-up, THA resulted in significantly greater improvements in pain (mean difference [MD] 35.4; 95% CI [confidence interval] 31.4 to 39.4), function (MD 30.5; 95% CI 26.3 to 34.7), and quality of life (MD 33.6; 95% CI 28.8 to 38.4). Between 17 and 30% of patients receiving Edu+Ex experienced a surgical threshold for clinically meaningful improvement in outcomes, compared to 84 and 90% of THA patients. CONCLUSIONS: A THA provides greater improvements in pain, function, and quality of life. A significant proportion of Edu+Ex patients had clinically meaningful improvements, suggesting Edu+Ex may result in THA deferral in some patients, but confirmatory trials are needed.

Challenges in the Metabolomics-Based Biomarker Validation Pipeline.

As end-products of the intersection between the genome and environmental influences, metabolites represent a promising approach to the discovery of novel biomarkers for diseases. However, many potential biomarker candidates identified by metabolomics studies fail to progress beyond analytical validation for routine implementation in clinics. Awareness of the challenges present can facilitate the development and advancement of innovative strategies that allow improved and more efficient applications of metabolite-based markers in clinical settings. This minireview provides a comprehensive summary of the pre-analytical factors, required analytical validation studies, and kit development challenges that must be resolved before the successful translation of novel metabolite biomarkers originating from research. We discuss the necessity for strict protocols for sample collection, storage, and the regulatory requirements to be fulfilled for a bioanalytical method to be considered as analytically validated. We focus especially on the blood as a biological matrix and liquid chromatography coupled with tandem mass spectrometry as the analytical platform for biomarker validation. Furthermore, we examine the challenges of developing a commercially viable metabolomics kit for distribution. To bridge the gap between the research lab and clinical implementation and utility of relevant metabolites, the understanding of the translational challenges for a biomarker panel is crucial for more efficient development of metabolomics-based precision medicine.

When Should I Get My Next COVID Vaccine? Data from the SUrveillance of responses to COVID-19 vaCcines in systEmic immunE mediated inflammatory Diseases (SUCCEED)study.

OBJECTIVE: To determine how serologic responses to COVID vaccination/infection in immunemediated inflammatory disease (IMID) are affected by time since last vaccination and other factors. METHODS: Post-COVID-19 vaccination, data and dried blood spots/sera were collected from adults with rheumatoid arthritis, inflammatory bowel disease, systemic lupus, ankylosing spondylitis/spondylarthritis and psoriasis/psoriatic arthritis. First sample was at enrolment and then 2-4 weeks and 3, 6, and 12 months after latest vaccine dose. Multivariate generalized estimating equation regressions (including medications, demographics, and vaccination history) evaluated serologic response, based on log-transformed anti-RBD IgG titres; we also measured anti-nucleocapsid IgG. RESULTS: Positive associations for log-transformed anti-RBD titres were seen with female sex, number of doses, and self-reported COVID infections in 2021-2023. Negative associations were seen with prednisone, anti-TNF agents, and rituximab.Over 2021-2023, most (94%) of anti-nucleocapsid positivity was associated with a self-reported infection in the 3 months prior. From March 2021 to Feb 2022, anti-nucleocapsid positivity was present in 5-15% of samples and was highest in the post-Omicron era, with anti-nucleocapsid positivity trending to 30-35% or higher as of March 2023. Anti-nucleocapsid positivity in IMID remained lower than Canada's general population seroprevalence (>50% in 2022 and >75% in 2023).Time since last vaccination was negatively associated with log-transformed anti-RBD titres, particularly after 210 days. CONCLUSION: Ours is the first pan-Canadian IMID assessment of how vaccine history and other factors affect serologic COVID-19 vaccine responses. These findings may help individuals personalize vaccination decisions, including consideration of additional vaccination when >6 months has elapsed since last COVID vaccination/infection.

Use of Apremilast to Achieve Psoriatic Arthritis Treatment Goals and Satisfaction at 1 Year in the Canadian Real-World APPRAISE Study.

INTRODUCTION: The APPRAISE study was conducted to better understand the 12-month effectiveness, tolerability, and patient satisfaction with apremilast treatment for patients with psoriatic arthritis (PsA) in real-world settings. METHODS: APPRAISE (NCT03608657), a prospective, multicenter, observational study, enrolled adults with active PsA prescribed apremilast per routine care between July 2018 and March 2020. Patients were followed for 12 months with visits suggested every 4 months. The primary outcome measure was achievement of remission (REM) or low disease activity (LDA), defined as a Clinical Disease Activity Index for Psoriatic Arthritis (cDAPSA) score ≤ 13. RESULTS: Of the 102 patients who enrolled, 45 (44.1%) discontinued the study by 12 months. Most patients (75.5%) had moderate or high disease activity, and 24.5% were in REM/LDA at baseline based on cDAPSA score. Achievement of cDAPSA REM/LDA was 63.7%, 67.2%, and 53.8% at months 4, 8, and 12, respectively. In those continuing in the study, significant improvements were seen in swollen and tender joint counts, pain visual analog scale, psoriasis body surface area, and complete dactylitis resolution. Enthesitis reduction was also observed. Improvements in treatment satisfaction and patient-reported outcomes, including Health Assessment Questionnaire-Disability Index and the 36-item Short Form physical and mental component scores, were observed over 12 months. The proportion of patients achieving a Patient-Acceptable Symptom State (PASS) increased significantly from baseline at months 4, 8, and 12 (P < 0.001). Apremilast was well tolerated; the most frequent adverse events (AEs) leading to discontinuation were diarrhea (9/102 [8.8%]), nausea (4/102 [3.9%]), and migraine (4/102 [3.9%]). CONCLUSION: In this real-world study conducted in Canadian rheumatology clinics, apremilast demonstrated clinical effectiveness in patients with active PsA, along with patient satisfaction with treatment. Safety findings were consistent with previously reported clinical data. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT03608657.

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.

Total Knee Arthroplasty Versus Education and Exercise for Knee Osteoarthritis: A Propensity-Matched Analysis.

OBJECTIVE: We estimate the treatment effect of total knee arthroplasty (TKA) versus an education and exercise (Edu+Ex) program on pain, function, and quality of life outcomes 3 and 12 months after treatment initiation for knee osteoarthritis (OA). METHODS: Patients with knee OA who had undergone TKA were matched on a 1:1 ratio with participants in an Edu+Ex program based on a propensity score fitted to a range of pretreatment covariates. After matching, between-group differences in improvement (the treatment effect) in Knee Injury and Osteoarthritis Outcome Score 12-item version (0, worst to 100, best) pain, function, and quality of life from baseline to 3 and 12 months were estimated using linear mixed models, adjusting for unbalanced covariates, if any, after matching. RESULTS: The matched sample consisted of 522 patients (Edu+Ex, n = 261; TKA, n = 261) who were balanced on all pretreatment characteristics. At 12-month follow-up, TKA resulted in significantly greater improvements in pain (mean difference [MD] 22.8; 95% confidence interval [95% CI] 19.7-25.8), function (MD 21.2; 95% CI 17.7-24.4), and quality of life (MD 18.3; 15.0-21.6). Even so, at least one-third of patients receiving Edu+Ex had a clinically meaningful improvement in outcomes at 12 months compared with 75% of patients with TKA. CONCLUSION: TKA is associated with greater improvements in pain, function, and quality of life, but these findings also suggest that Edu+Ex may be a viable alternative to TKA in a meaningful proportion of patients, which may reduce overall TKA need. Confirmatory trials are needed.

Classifying patients with psoriatic arthritis according to their disease activity status using serum metabolites and machine learning.

INTRODUCTION: Psoriatic arthritis (PsA) is a heterogeneous inflammatory arthritis, affecting approximately a quarter of patients with psoriasis. Accurate assessment of disease activity is difficult. There are currently no clinically validated biomarkers to stratify PsA patients based on their disease activity, which is important for improving clinical management. OBJECTIVES: To identify metabolites capable of classifying patients with PsA according to their disease activity. METHODS: An in-house solid-phase microextraction (SPME)-liquid chromatography-high resolution mass spectrometry (LC-HRMS) method for lipid analysis was used to analyze serum samples obtained from patients classified as having low (n = 134), moderate (n = 134) or high (n = 104) disease activity, based on psoriatic arthritis disease activity scores (PASDAS). Metabolite data were analyzed using eight machine learning methods to predict disease activity levels. Top performing methods were selected based on area under the curve (AUC) and significance. RESULTS: The best model for predicting high disease activity from low disease activity achieved AUC 0.818. The best model for predicting high disease activity from moderate disease activity achieved AUC 0.74. The best model for classifying low disease activity from moderate and high disease activity achieved AUC 0.765. Compounds confirmed by MS/MS validation included metabolites from diverse compound classes such as sphingolipids, phosphatidylcholines and carboxylic acids. CONCLUSION: Several lipids and other metabolites when combined in classifying models predict high disease activity from both low and moderate disease activity. Lipids of key interest included lysophosphatidylcholine and sphingomyelin. Quantitative MS assays based on selected reaction monitoring, are required to quantify the candidate biomarkers identified.

Derivation and Internal Validation of a Disease-Specific Cardiovascular Risk Prediction Model for Patients With Psoriatic Arthritis and Psoriasis.

OBJECTIVE: To address suboptimal cardiovascular risk prediction in patients with psoriatic disease (PsD), we developed and internally validated a five-year disease-specific cardiovascular risk prediction model. METHODS: We analyzed data from a prospective cohort of participants with PsD without a history of cardiovascular events. Traditional cardiovascular risk factors and PsD-related measures of disease activity were considered as potential predictors. The study outcome included nonfatal and fatal cardiovascular events. A base prediction model included 10 traditional cardiovascular risk factors. Eight PsD-related factors were assessed by adding them to the base model to create expanded models, which were controlled for PsD therapies. Variable selection was performed using Least Absolute Shrinkage and Selection Operator (LASSO) penalized regression with 10-fold cross-validation. Model performance was assessed using measures of discrimination and calibration and measures of sensitivity and specificity. RESULTS: Between 1992 and 2020, 85 of 1,336 participants developed cardiovascular events. Discrimination of the base model (with traditional cardiovascular risk factors alone) was excellent, with an area under the receiver operator characteristic curve (AUC) of 85.5 (95% confidence interval [CI] 81.9-89.1). Optimal models did not select any of the tested disease-specific factors. In a sensitivity analysis, which excluded lipid lowering and antihypertensive treatments, the number of damaged joints was selected in the expanded model. However, this model did not improve risk discrimination compared to the base model (AUC 85.5, 95% CI 82.0-89.1). CONCLUSION: Traditional cardiovascular risk factors alone are effective in predicting cardiovascular risk in patients with PsD. A risk score based on these factors performed well, indicating excellent discrimination and calibration.

Pharmacodynamic effects of filgotinib treatment driving clinical improvement in patients with active psoriatic arthritis enrolled in the EQUATOR trial.

OBJECTIVES: The goal of this study was to identify protein and transcriptional biomarkers and pathways associated with baseline disease state, the effect of filgotinib (FIL) treatment on these biomarkers, and to investigate the mechanism of action of FIL on clinical improvement in patients with active psoriatic arthritis (PsA). METHODS: The phase II EQUATOR (NCT03101670) trial evaluated the efficacy of FIL, a Janus kinase 1-preferential inhibitor, in patients with PsA. Peripheral protein and gene expression levels in association with clinical state at baseline and post-treatment were assessed in 121 patients using linear mixed effects models for repeated measures analyses. Mediation analysis and structural equation modelling (SEM) were performed to investigate the mechanism of action of FIL at week 4 on downstream clinical improvement at week 16. RESULTS: Baseline analyses showed that markers of inflammation were significantly associated with multiple PsA clinical metrics, except for Psoriasis Area and Severity Index (PASI), which corresponded to Th17 markers. FIL treatment resulted in sustained transcriptional inhibition of immune genes and pathways, a sustained increase in B-cell fraction and mature B-cells in circulation, and a transient effect on other cell fractions. Mediation analysis revealed that changes in B cells, systemic inflammatory cytokines and neutrophils at week 4 were associated with changes in clinical metrics at week 16. SEM suggested that FIL improved PASI through reduction of IL-23 p19 and IL-12 p40 proteins. CONCLUSIONS: Our results revealed that FIL treatment rapidly downregulates inflammatory and immune pathways associated with PsA disease activity corresponding to clinical improvement in PsA. TRIAL REGISTRATION NUMBER: NCT03101670.

Identifying Serum Metabolomic Markers Associated with Skin Disease Activity in Patients with Psoriatic Arthritis.

Psoriatic arthritis (PsA) is a chronic, systemic, immune-mediated inflammatory disease causing cutaneous and musculoskeletal inflammation that affects 25% of patients with psoriasis. Current methods for evaluating PsA disease activity are not accurate enough for precision medicine. A metabolomics-based approach can elucidate psoriatic disease pathogenesis, providing potential objective biomarkers. With the hypothesis that serum metabolites are associated with skin disease activity, we aimed to identify serum metabolites associated with skin activity in PsA patients. We obtained serum samples from patients with PsA (n = 150) who were classified into mild, moderate and high disease activity groups based on the Psoriasis Area Severity Index. We used solid-phase microextraction (SPME) for sample preparation, followed by data acquisition via an untargeted liquid chromatography-mass spectrometry (LC-MS) approach. Disease activity levels were predicted using identified metabolites and machine learning algorithms. Some metabolites tentatively identified include eicosanoids with anti- or pro-inflammatory properties, like 12-Hydroxyeicosatetraenoic acid, which was previously implicated in joint disease activity in PsA. Other metabolites of interest were associated with dysregulation of fatty acid metabolism and belonged to classes such as bile acids, oxidized phospholipids, and long-chain fatty acids. We have identified potential metabolites associated with skin disease activity in PsA patients.

Risankizumab for the treatment of active psoriatic arthritis in adults.

INTRODUCTION: Psoriatic arthritis (PsA) is a chronic rheumatic disease that displays a variety of clinical manifestations. Although new treatments have emerged over the last 2 decades, challenges remain in controlling inflammation in multiple PsA clinical domains. AREAS COVERED: Risankizumab, one of the biologic disease modification anti-rheumatic drugs (bDMARDs) that target the interleukin (IL)-23 p19 subunit, was recently approved for PsA worldwide. This review primarily highlights the recent clinical trials of risankizumab covering its physiological evaluation, patient-reported outcomes, and safety profiles in patients with PsA. We also provide evidence for anti-IL-23 therapies against extra-articular manifestations and axial symptoms of PsA. Furthermore, potential distinct efficacies and mechanisms of action in anti-IL-23 therapies are discussed. Overall, risankizumab is effective in a variety of clinical signs and symptoms of PsA regardless of prior bDMARDs experience. EXPERT OPINION: Accumulating evidence shows that anti-IL-23 drugs, including risankizumab, are promising treatments that can be used as first- or second-line therapies for PsA. However, multiple challenges remain, including confirming efficacy for axial symptoms and identifying the phenotype of specific patients who respond better to risankizumab than other drugs. Lastly, future data focusing on the long-term efficacy and safety of risankizumab beyond the 1-year observation period are also needed.

Autoantibodies in psoriatic disease.

Psoriasis is an inflammatory skin disease affecting over 8 million people in the US and Canada. Approximately, a quarter of psoriasis patients have an inflammatory arthritis termed psoriatic arthritis (PsA). Psoriatic disease encompassing both psoriasis and PsA is regarded as an immune-mediated inflammatory disease, exhibiting both autoimmune and autoinflammatory features. A review of the current literature on the presence and clinical significance of autoantibodies found in psoriatic disease are presented. The frequency of several autoantibodies in psoriasis and PsA patients as well as their clinical significance regarding disease diagnosis, disease activity and treatment response are reviewed. Additionally, the basic principles of antibody assays are presented, and the methods used for each study are analyzed. Despite historically described as a rheumatoid factor negative (seronegative) disease, an array of autoantibodies has been identified in patients with psoriatic disease. This points to an autoimmune component potentially playing a role in psoriatic disease; however, additional evidence is needed to determine the clinical utility of these autoantibodies.

Psoriatic Arthritis and COVID-19: Patient Perspectives in a Large Psoriatic Arthritis Cohort.

OBJECTIVE: To estimate the prevalence of coronavirus disease 2019 (COVID-19) infection among patients with psoriatic arthritis (PsA), understand patients' perspectives regarding their risk of COVID-19 infection, and evaluate the standard of virtual care offered during the early phases of the pandemic. METHODS: An online survey was conducted between June 2021 and September 2021 in patients with PsA who had consented to email contact. The survey was completed by 152/193 (79%) patients who had consented to the study. RESULTS: There were 86 (56.6%) men and 66 (43.4%) women with a mean age of 58 years and mean disease duration of 19 years. During the pandemic, the mean patient-reported symptom severity was 4.10, 3.24, and 3.72 for joint, skin, and overall symptom severity, respectively. Seventy-four percent of respondents would accept the effect of their PsA over the past month for the next few months. Of 79 patients who were tested for severe acute respiratory syndrome coronavirus 2, 4 tested positive. All 4 were admitted to hospital; 2 required oxygen. One hundred fifty-one patients (99%) had received at least 1 vaccine dose. Fifty-nine (38.8%) participants believed their PsA medications increased their COVID-19 infection risk. Of the 130 patients who had a telemedicine assessment, 83.1% were happy with their virtual consultations. Most were happy to continue with virtual consultations until the pandemic resolved. The average satisfaction level regarding pandemic care was 7.87 on a sliding 10-point scale. CONCLUSION: COVID-19 prevalence was low among our patients. Patients were satisfied with their care during the pandemic. Most patients would happily continue with virtual care for the duration of the pandemic.

Investigational monoclonal antibodies in early development for psoriatic arthritis: beyond the biosimilars.

INTRODUCTION: Psoriatic Arthritis (PsA) is an inflammatory arthritis that is present in approximately 25% of psoriasis patients. Currently, several targeted therapies are available to manage PsA; however, many patients fail these therapies. Several new therapeutic options, with differing mechanisms of action, are currently being evaluated. AREAS COVERED: This article reviews available results from phase I to phase III trials of several investigational monoclonal antibodies that the FDA has not yet approved for PsA. The proposed mechanisms of the new therapeutic agents and their relevance to the pathogenesis of PsA will be discussed. The investigational agents' efficacy and safety will be summarized, and their potential clinical applications for managing PsA will be contemplated. EXPERT OPINION: Due to recent advances in understanding psoriatic arthritis, therapeutic agents are increasingly focused on inhibiting interleukin-17 and interleukin-23 pathways. Various strategies have been used to inhibit these cytokines, demonstrating favorable efficacy and acceptable safety profile.

Novel Insights From Basic Science in Psoriatic Disease at the GRAPPA 2022 Annual Meeting.

Recent basic science advances in psoriatic disease (PsD) were presented and discussed at the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) 2022 annual meeting. Topics included clinical applications of biomarkers, what the future of biomarkers for PsD may hold, the challenges of developing biomarker research to the point of clinical utility, advances in total-body positron emission tomography/computed tomography imaging, and emerging concepts from single-cell studies in PsD.

Proceedings of the GRAPPA 2022 Executive Retreat.

The Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) leadership congregated for a strategic planning meeting before the 2022 GRAPPA annual meeting in New York, USA. Meeting aims were to review GRAPPA's performance in relation to its 2016 goals and identify successes and areas for further improvement, identify key GRAPPA priorities and activities for the next 5 years, and explore committee structures to best support these aims.

Proceedings of the Collaborative Research Network Meeting at the GRAPPA 2022 Annual Meeting.

At the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) 2022 annual meeting, the Collaborative Research Network (CRN) met to present updates on several projects. These included the GRAPPA-Industry biomarker projects, Axial Psoriatic Arthritis Molecular and Clinical Characterisation Study, Axial Involvement in Psoriatic Arthritis Cohort (AXIS) study, and the Health Initiatives in Psoriasis and Psoriatic Arthritis Consortium European States (HIPPOCRATES). The meeting concluded with a discussion on pathways to further academia-industry collaboration.

Impact of COVID-19 on Patients With Psoriasis or Psoriatic Arthritis.

Given the impact of the coronavirus disease 2019 (COVID-19) on patients with psoriatic disease (PsD), a session was devoted at the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) 2022 annual meeting to discussing the current understanding of the risk of severe COVID-19 in patients with PsD. The effects of PsD and its treatment on prevention and treatment of COVID-19 with vaccinations, antiviral drugs, and monoclonal antibodies were discussed. The session concluded with a presentation on the perspectives of patient research partners about their experiences with COVID-19.

A Solid-Phase Microextraction-Liquid Chromatography-Mass Spectrometry Method for Analyzing Serum Lipids in Psoriatic Disease.

Approximately 25% of psoriasis patients have an inflammatory arthritis termed psoriatic arthritis (PsA). There is strong interest in identifying and validating biomarkers that can accurately and reliably predict conversion from psoriasis to PsA using novel technologies such as metabolomics. Lipids, in particular, are of key interest in psoriatic disease. We sought to develop a liquid chromatography-mass spectrometry (LC-MS) method to be used in conjunction with solid-phase microextraction (SPME) for analyzing fatty acids and similar molecules. A total of 25 chromatographic methods based on published lipid studies were tested on two LC columns. As a proof of concept, serum samples from psoriatic disease patients (n = 27 psoriasis and n = 26 PsA) were processed using SPME and run on the selected LC-MS method. The method that was best for analyzing fatty acids and fatty acid-like molecules was optimized and applied to serum samples. A total of 18 tentatively annotated features classified as fatty acids and other lipid compounds were statistically significant between psoriasis and PsA groups using both multivariate and univariate approaches. The SPME-LC-MS method developed and optimized was capable of detecting fatty acids and similar lipids that may aid in differentiating psoriasis and PsA patients.

Derivation of a Multivariable Psoriatic Arthritis Risk Estimation Tool (PRESTO): A Step Towards Prevention.

OBJECTIVE: A simple, scalable tool that identifies psoriasis patients at high risk for developing psoriatic arthritis (PsA) could improve early diagnosis. We aimed to develop a risk prediction model for the development of PsA and to assess its performance among patients with psoriasis. METHODS: We analyzed data from a prospective cohort of psoriasis patients without PsA at enrollment. Participants were assessed annually by a rheumatologist for the development of PsA. Information about their demographics, psoriasis characteristics, comorbidities, medications, and musculoskeletal symptoms was used to develop prediction models for PsA. Penalized binary regression models were used for variable selection while adjusting for psoriasis duration. Risks of developing PsA over 1- and 5-year time periods were estimated. Model performance was assessed by the area under the curve (AUC) and calibration plots. RESULTS: Among 635 psoriasis patients, 51 and 71 developed PsA during the 1-year and 5-year follow-up periods, respectively. The risk of developing PsA within 1 year was associated with younger age, male sex, family history of psoriasis, back stiffness, nail pitting, joint stiffness, use of biologic medications, patient global health, and pain severity (AUC 72.3). The risk of developing PsA within 5 years was associated with morning stiffness, psoriatic nail lesion, psoriasis severity, fatigue, pain, and use of systemic nonbiologic medication or phototherapy (AUC 74.9). Calibration plots showed reasonable agreement between predicted and observed probabilities. CONCLUSIONS: The development of PsA within clinically meaningful time frames can be predicted with reasonable accuracy for psoriasis patients using readily available clinical variables.