Model-based cost-effectiveness analyses comparing combinations of urate lowering therapy and anti-inflammatory treatment in gout patients.

OBJECTIVES: To assess the cost-effectiveness of various combinations of urate lowering therapy (ULT) and anti-inflammatory treatment in the management of newly diagnosed gout patients, from the Dutch societal perspective. METHODS: A probabilistic patient-level simulation estimating costs and quality-adjusted life years (QALYs) comparing gout and hyperuricemia treatment strategies was performed. ULT options febuxostat, allopurinol and no ULT were considered. Flare treatments naproxen, colchicine, prednisone, and anakinra were considered. A Markov Model was constructed to simulate gout disease. Health states were no flare, and severe pain, mild pain, moderate pain, or no pain in the presence of a flare. Model input was derived from patient level clinical trial data, meta-analyses or from previously published health-economic evaluations. The results of probabilistic sensitivity analyses were presented using incremental cost-effectiveness ratios (ICERs), and summarized using cost-effectiveness acceptability curves (CEACs). Scenario analyses were performed. RESULTS: The ICER for allopurinol versus no ULT was €1,381, when combined with naproxen. Febuxostat yielded the highest utility, but also the highest costs (€4,385 vs. €4,063 for allopurinol), resulting in an ICER of €25,173 when compared to allopurinol. No ULT was not cost-effective, yielding the lowest utility. For the gout flare medications, comparable effects on utility were achieved. Combined with febuxostat, naproxen was the cheapest option (€4,404), and anakinra the most expensive (€4,651). The ICER of anakinra compared to naproxen was €818,504. Colchicine and prednisone were dominated by naproxen. CONCLUSION: Allopurinol and febuxostat were both cost-effective compared to No ULT. Febuxostat was cost-effective in comparison with allopurinol at higher willingness-to-pay thresholds. For treating gout flares, colchicine, naproxen and prednisone offered comparable health economic implications, although naproxen was the favoured option.

Common Functional Ability Score for Young People With Juvenile Idiopathic Arthritis.

OBJECTIVE: As young people enter adulthood, the interchangeable use of child and adult outcome measures may inaccurately capture changes over time. This study aimed to use item response theory (IRT) to model a continuous score for functional ability that can be used no matter which questionnaire is completed. METHODS: Adolescents (ages 11-17 years) in the UK Childhood Arthritis Prospective Study (CAPS) self-completed an adolescent Childhood Health Assessment Questionnaire (CHAQ) and a Health Assessment Questionnaire (HAQ). Their parents answered the proxy-completed CHAQ. Those children with at least 2 simultaneously completed questionnaires at initial presentation or 1 year were included. Psychometric properties of item responses within each questionnaire were tested using Mokken analyses to assess the applicability of IRT modeling. A previously developed IRT model from the Pharmachild-NL registry from The Netherlands was validated in CAPS participants. Agreement and correlations between IRT-scaled functional ability scores were tested using intraclass correlations and Wilcoxon's signed rank tests. RESULTS: In 303 adolescents, the median age at diagnosis was 13 years, and 61% were female. CHAQ scores consistently exceeded HAQ scores. Mokken analyses demonstrated high scalability, monotonicity, and the fact that each questionnaire yielded reliable scores. There was little difference in item response characteristics between adolescents enrolled in CAPS and Pharmachild-NL (maximum item residual 0.08). Significant differences were no longer evident between IRT-scaled HAQ and CHAQ scores. CONCLUSION: IRT modeling allows the direct comparison of function scores regardless of different questionnaires being completed by different people over time. IRT modeling facilitates the ongoing assessment of function as adolescents transfer from pediatric clinics to adult services.

Two parallel short forms to measure disease- and treatment-associated knowledge in rheumatoid arthritis: application of item response theory.

OBJECTIVE: The aim was to develop two disease- and treatment-related knowledge about RA (DataK-RA) short forms using item response theory-based linear optimal test design. METHODS: We used the open source Excel add-in solver to program a linear optimization algorithm to develop two short forms from the DataK-RA item bank. The algorithm was instructed to optimize precision (i.e. reliability) of the scores for both short forms, subject to a number of constraints that served to ensure that each short form would include unique items and that the short forms would have similar psychometric properties. Agreement among item response theory scores obtained from the different short forms was assessed using the Bland-Altman method and Student's paired t-test. Construct validity and relative efficiency of the short forms was evaluated by relating the score to age, sex and educational attainment. RESULTS: Two short forms were derived from the DataK-RA item bank that satisfied all content constraints. Both short forms included 15 unique items and yielded reliable scores (r > 0.70), with low ceiling and floor effects. The short forms yielded statistically indistinguishable mean scores according to Student's paired t-test and Bland-Altman analysis. Scores on short forms 1 and 2 were associated with age, sex and educational attainment to a similar extent. CONCLUSION: In this study, we developed two DataK-RA short forms with unique items, yet similar psychometric properties, that can be used to assess patients pre- and post-test interventions aimed at improving disease-related knowledge in RA patients.

The long and winding road to happiness: A randomized controlled trial and cost-effectiveness analysis of a positive psychology intervention for lonely people with health problems and a low socio-economic status.

BACKGROUND: Our objective was to evaluate the effectiveness and cost-effectiveness of the positive psychology intervention 'Happiness Route' compared to an active control condition in a vulnerable population with an accumulation of health and psychosocial problems. METHODS: We conducted a randomized, single-blind, actively-controlled, parallel group study in seven municipalities in the Netherlands. To be eligible, participants had to experience loneliness, health problems and low socio-economic status. Each group received several home visits by a counsellor (two in the control condition, two to six in the experimental condition). In the Happiness Route, a happiness-based approach was used, whereas the control condition used a traditional problem-based approach. The primary outcome was well-being, measured with the Mental Health Continuum-Short Form (MHC-SF). RESULTS: Fifty-eight participants were randomized to the Happiness Route, 50 to the control condition. Participants were severely lonely, had on average three health problems and less than 5% had paid work. The total MHC-SF score, emotional and social well-being, depression and loneliness improved significantly over the nine-month period in both conditions (p < .05), but there were no significant changes between the conditions across time. Languishing decreased significantly from 33% at baseline to 16% at follow-up among the Happiness Route participants but did not change significantly in the control condition. No significant improvement over time was found in psychological well-being, resilience, purpose in life, health-related quality of life and social participation. Cost-effectiveness analysis showed that expected saved costs per QALY lost was €219,948 for the Happiness Route, relative to the control condition. The probability was 83% that the Happiness Route was cost saving and 54% that the Happiness Route was cost-effective at a willingness to accept a threshold of €100,000. CONCLUSIONS: Mental health status of both groups improved considerably. However, we could not demonstrate that the Happiness Route yielded better health outcomes compared to the control condition. Nevertheless, the results of the cost-effectiveness analysis suggested that the Happiness Route is an acceptable intervention from a health-economic point of view. Our results should be viewed in light of the fact that we could not include the planned number of participants. TRIAL REGISTRATION: Netherlands Trial Register: NTR3377. Registered 2 Apr 2012.

Cost-Effectiveness of a JAK1/JAK2 Inhibitor vs a Biologic Disease-Modifying Antirheumatic Drug (bDMARD) in a Treat-to-Target Strategy for Rheumatoid Arthritis.

BACKGROUND: Baricitinib is a janus kinase (JAK1/JAK2) inhibitor developed for the treatment of patients suffering from rheumatoid arthritis (RA). Treating RA to the target of remission is current common practice. Cost-effectiveness of different treat-to-target (T2T) strategies, especially ones including new treatments is important for development and preference policy for treatment centers. European League Against Rheumatism (EULAR) and American College of Rheumatology (ACR) guidelines are currently unclear about preference between a JAK1/JAK2 versus a biological disease-modifying antirheumatic drug (bDMARD). OBJECTIVE: The main goal of this paper was to evaluate the cost-effectiveness of baricitinib versus first biological for methotrexate inadequate responders in a T2T strategy using a Markov model that incorporates hospital costs as well as societal costs. Costs and utilities over five years were compared between the two strategies. METHODS: A Monte Carlo simulation model was developed to conduct cost-utility analysis from the societal perspective over 5 years. Health states were based on the DAS28-erythrocyte sedimentation rate (ESR) categories. Effectiveness of baricitinib was retrieved from randomized controlled trials. Effectiveness of all other treatments, health state utilities, medical costs, and productivity loss were retrieved from the Dutch RhEumatoid Arthritis Monitoring (DREAM) cohorts. Annual discount rates of 1.5% for utility and 4% for costs were used. Probabilistic sensitivity analysis was employed to incorporate uncertainty and assess robustness of the results. RESULTS: Probabilistic sensitivity analysis results showed the baricitinib strategy yielded lower costs and higher utility over a 5-year period. Scenario analyses showed the baricitinib strategy to be cost-effective in both the moderate and severe RA populations. CONCLUSION: Results suggest that the use of a JAK1/JAK2 inhibitor instead of a bDMARD in a T2T approach is cost-effective in csDMARD refractory RA patients.

Radiographic progression can still occur in individual patients with low or moderate disease activity in the current treat-to-target paradigm: real-world data from the Dutch Rheumatoid Arthritis Monitoring (DREAM) registry.

BACKGROUND: The aim of this retrospective study was to examine the longitudinal association between disease activity and radiographic damage in a cohort of patients with early RA (symptom onset < 1 year) treated according to treat-to-target (T2T) therapy. METHODS: Baseline to 3-year follow-up data were used from patients included in the DREAM remission induction cohort. Patients received protocolized T2T treatment, aimed at 28-joint disease activity score-erythrocyte sedimentation rate (DAS28-ESR) remission. Disease activity (DAS28-ESR and C-reactive protein, CRP) were assessed at least every 3 months; X-rays of the hand and feet at inclusion, 6 months, and 1, 2, and 3 years were scored using modified Sharp/van der Heijde scoring (SHS). Between and within-person associations between time-integrated disease activity and radiographic progression over time were examined. RESULTS: A subset of 229 out of 534 included patients were available for analysis. At the between-patient level, time-integrated DAS28-ESR scores were not significantly correlated with progression at the 6 month and 2-year follow-up and only weakly at the 1-year (Pearson's correlation coefficient r = 0.17, P < 0.05) and 3-year follow-up (r = 0.21, P < 0.05). Individual slopes of the relationship between DAS28-ESR and progression scores in each time interval were significantly correlated over time and the slope of the first 6 months was moderately associated with this slope at later time points (r between 0.39 and 0.59; P values < 0.001). Between 15.9 to 22.7% and 16.7 to 38.5% of patients with low and moderate time-integrated disease activity, respectively, experienced relevant (ΔSHS ≥ 3) radiographic progression at the different time intervals. Analyses using CRP showed similar results. CONCLUSIONS: In early RA patients treated according to T2T, radiographic progression appears to be an individually determined disease process, driven by factors other than consistent high disease activity. For individual patients, the intra-patient relation between disease activity and cumulative radiographic damage during the first 6 months is a good indicator for this relation in later years. TRIAL REGISTRATION: Netherlands Trial Register NTR578, 12 January 2006.

Taking the patient and the patient's perspective into account to improve outcomes of care of patients with musculoskeletal diseases.

Patient-reported outcome measures are commonly used in the assessment of patients with musculoskeletal diseases. The present review provides an overview of historic and recent developments, including core set recommendations for assessing patient-reported outcomes in patients with fibromyalgia, osteoarthritis, rheumatoid arthritis, ankylosing spondylitis, and psoriatic arthritis. The evidence supporting commonly used patient-reported outcomes measures is reviewed. Furthermore, various methodological approaches that can be utilized to evaluate validity and measurement precision of patient reported outcomes are introduced. Commonly used methods based on the classical test theory as well as modern approaches based on item response theory will be discussed. The review finally describes the increasing use of item response theory-based approaches used in patient-reported outcomes assessment in the musculoskeletal diseases.

Cost-effectiveness of different treat-to-target strategies in rheumatoid arthritis: results from the DREAM registry.

BACKGROUND: Adjusting medication of patients with rheumatoid arthritis (RA) until predefined disease activity targets are met, i.e. Treat-to-Target (T2T), is the currently recommended treatment approach. However, not much is known about long-term cost-effectiveness of different T2T strategies.We model the 5-year costs and effects of a step-up approach (MTX mono - > MTX + csDMARD combination - > Adalimumab - > second anti-TNF) and an initial combination therapy approach (MTX + csDMARD - > MTX + csDMARD higher dose - > anti-TNFs) from the healthcare and societal perspectives, by adapting a previously validated Markov model. METHODS: We constructed a Markov model in which 3-monthly transitions between DAS28-defined health states of remission (≤2.6), low (2.6 < DAS28 ≤ 3.2), moderate (3.2 < DAS28 ≤ 5.1), and high disease activity (DAS28 > 5.1) were simulated. Modelled patients proceeded to subsequent treatments in case of non-remission at each (3-month) cycle start. In case of remission for two consecutive cycles medication was tapered, until medication-free remission was achieved. Transition probabilities for individual treatment steps were estimated using data of Dutch Rheumatology Monitoring registry Remission Induction Cohort I (step-up) and II (initial combination). Expected costs, utility, and ICER after 5 years were compared between the two strategies. To account for parameter uncertainty, probabilistic sensitivity analysis was employed through Gamma, Normal, and Dirichlet distributions. All utilities, costs, and transition probabilities were replaced by fitted distributions. RESULTS: Over a 5-year timespan, initial combination therapy was less costly and more effective than step-up therapy. Initial combination therapy accrued €16,226.3 and 3.552 QALY vs €20,183.3 and 3.517 QALYs for step-up therapy. This resulted in a negative ICER, indicating that initial combination therapy was both less costly and more effective in terms of utility gained. This can be explained by higher (±5%) remission percentages in initial combination strategy at all time points. More patients in remission generates less healthcare and productivity loss costs and higher utility. Additionally, higher remission percentages caused less bDMARD use in the initial combination strategy, lowering overall costs. CONCLUSION: Initial combination therapy was found favourable over step-up therapy in the treatment of Rheumatoid Arthritis, when considering cost-effectiveness. Initial combination therapy resulted in more utility at a lower cost over 5 years.

Long-term clinical, functional, and cost outcomes for early rheumatoid arthritis patients who did or did not achieve early remission in a real-world treat-to-target strategy.

OBJECTIVE: To retrospectively compare the long-term clinical, functional, and cost outcomes for early RA patients (symptoms < 1 year) who did or did not achieve early remission in a treat-to-target strategy. METHOD: Five-year data of 471 patients included in the DREAM remission induction cohort were used. Patients were treated according to a pre-specified 28-joint Disease Activity Score (DAS28) remission driven step-up treatment strategy starting with methotrexate, addition of sulfasalazine, and exchange of sulfasalazine for biological medication in case of failure. Two- and 3-year healthcare costs were available for selected subsamples of patients only. RESULTS: DAS28 remission was achieved in 27.7%, 38.2%, and 51.6% of patients at 2, 3, and 6 months, respectively. Achieving DAS28 remission at 2, 3, or 6 months was consistently associated with significantly lower DAS28 and Health Assessment Questionnaire-Disability scores at 1, 3, and 5 years of follow-up (all P values < 0.02). Patients in remission at 2, 3, or 6 months also had significantly lower medication costs per patient over the first 2 and 3 years of treatment, mainly due to lower biologic use, but differences in total healthcare resource costs (hospital admissions plus consultations) were less pronounced. Mean total medication and total healthcare resource costs at 3 years were €1131 and €1757 for patients in remission at 6 months vs. €7533 (P < 0.01) and €2202 (P = 0.09) for those not in remission. CONCLUSION: Achieving early remission was associated with beneficial clinical outcomes for early RA patients and lower costs in the long term. Key Points • Previous studies in rheumatoid arthritis patients have demonstrated that early good response is associated with sustained remission and better long-term clinical outcomes. • This study extents these findings by examining the long-term benefits of achieving early remission on clinical, patient-reported, and economic outcomes in a real-world cohort of patients with very early rheumatoid arthritis treated according to treat-to-target principles. • The findings of this study clearly demonstrate that aiming for early remission in rheumatoid arthritis patients is beneficial in the long-term in terms of better clinical and functional outcomes and lower healthcare costs.

A systematic literature review of patient-reported outcome measures used in gout: an evaluation of their content and measurement properties.

BACKGROUND: Gout is a common, monosodium urate crystal-driven inflammatory arthritis. Besides its clinical manifestations, patients often also suffer from pain, physical impairment, emotional distress and work productivity loss, as a result of the disease. Patient-reported outcome measures (PROMs) are commonly used to assess these consequences of the disease. However, current instrument endorsements for measuring such outcomes in acute and chronic gout clinical settings are based on limited psychometric evidence. The objective of this systematic literature review was to identify currently available PROMs for gout, and to critically evaluate their content and psychometric properties, in order to evaluate the current status regarding PROMs for use in gout patients. METHODS: Systematic literature searches were performed in the PubMed and EMBASE databases. The methodological quality of included papers was appraised using the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) checklist, and evaluation of measurement properties (reliability, responsiveness, construct validity, floor and ceiling effects) was done in accordance with published quality criteria. Item content was appraised by linking health concepts to the International Classification of Functioning Disability and Health (ICF) framework. RESULTS: In total, 13 PROMs were identified, of which three were targeted specifically at gout patients. The majority of the PROMs were rated positively for content validity. For most instruments, limited evidence was available for construct validity and reliability. Instruments to assess pain scored well on responsiveness and floor and ceiling effects, but not much is known about their reliability in gout. CONCLUSIONS: The physical functioning subscale of the SF-36v2 (Short Form-36 item version 2) is the only PROM that had sufficient supporting evidence for all its psychometric properties. Many of the commonly used PROMs in gout are currently not yet well supported and more studies on their measurement properties are needed among both acute and chronic gout populations.

Psychometric properties and cross-language equivalence of the revised Bristol Rheumatoid Arthritis Fatigue and the Rheumatoid Arthritis Impact of Disease scales in rheumatoid arthritis.

OBJECTIVE: To assess psychometric properties and cross-language measurement equivalence of six versions of the Bristol Rheumatoid Arthritis Fatigue Scale (BRAF-MDQ) and the Rheumatoid Arthritis Impact of Disease Score (RAID in rheumatoid arthritis (RA). METHODS: Both questionnaires were completed by French (n = 206), German (n = 206), Dutch (n = 317), Spanish (n = 157), Swedish (n = 170) and UK (n = 210) RA patients. The presence of cross-language differential item functioning (DIF) was examined using the generalized partial credit model. The impact of DIF on the item and total scores was examined by comparing DIF unadjusted and DIF adjusted expected item and scale scores. IRT-based methods were used to assess psychometric properties of the instruments. RESULTS: 11 of the 20 BRAF-MDQ (55%) and 4 of the 7 RAID items (57%) exhibited significant DIF in at least one of the six countries. The mean number of items with DIF per country was 2.6 for BRAF-MDQ and 1.1 for RAID. However, the impact of DIF on the total RAID and BRAF-MDQ scores, as well as the BRAF subscales, was found to be negligible at the group level. Only for the BRAF physical subscale was there evidence of minor DIF. Marginal reliabilities of BRAF-MDQ (0.93) and RAID (0.89) were excellent, and precise scores could be obtained across the spectrum of disease impact and fatigue scores measured by these PROMs. CONCLUSION: This study supports the cross-language measurement equivalence of BRAF-MDQ and RAID and provides further support for the psychometric properties of these measures in RA.

Development and validation of a patient-reported gout attack intensity score for use in gout clinical studies.

OBJECTIVE: Inflammation-related symptoms such as pain, swelling and tenderness of the affected joint are frequently assessed using 5-point diary rating scales in gout clinical trials. Combining these into a single gout attack symptom intensity score may be a useful summary measure for these data, which is potentially more responsive to change compared with the individual components. The objective of this study was to develop a patient-reported gout flare intensity score, the Gout Attack Intensity Score (GAIS), for use in clinical studies, that includes components for gout-related pain, swelling and tenderness. METHODS: Data from a randomized controlled trial comparing anakinra to standard of care for the treatment of acute gout attacks were used for this study. A 7-day flare diary was completed by patients, including questions relating to intensity of pain, swelling and tenderness (5-point rating scales). Scalability of these items was assessed using Mokken Scale Analysis, and reliability using greatest lower bound reliability coefficients. Known-groups validity was evaluated, as well as the responsiveness to change and the presence of floor and ceiling effects. RESULTS: Scalability of the single items was supported, and GAIS scores were reliable (greatest lower bound >0.80). GAIS scores demonstrated responsiveness to change with high effect sizes (>0.8), and discriminated better between responders and non-responders compared with its single-item components. No floor and ceiling effects were found. CONCLUSION: The GAIS seems to be a reliable and responsive instrument for assessing patient-reported gout attack intensity that may be used in gout clinical studies.

Anakinra for the treatment of acute gout flares: a randomized, double-blind, placebo-controlled, active-comparator, non-inferiority trial.

OBJECTIVES: To evaluate the efficacy and safety of anakinra in treating acute gout flares in a randomized, double-blind, placebo-controlled, active comparator, non-inferiority (NI) trial. METHODS: Patients with a crystal-proven acute gout flare were randomized (1: 1) to treatment with anakinra or treatment as usual (free choice: either colchicine, naproxen or prednisone). The primary end point was the change in pain between baseline and the averaged pain score on days 2-4 measured on a five-point rating scale. NI of anakinra would be established if the upper bound of the 95% CI of the numeric difference in changed pain scores between treatment groups did not exceed the NI limit of 0.4 in favour of treatment as usual, in the per-protocol (PP) and intention-to-treat (ITT) populations, assessed in an analysis of covariance model. Secondary outcomes included safety assessments, improvement in pain, swelling, tenderness and treatment response after 5 days, assessed using linear mixed models and binary logistic regression models. RESULTS: Forty-three patients received anakinra and 45 treatment as usual. Anakinra was non-inferior (mean difference; 95% CI) to treatment as usual in both the PP (-0.13; -0.44, 0.18) and ITT (-0.18; -0.44, 0.08) populations. No unexpected or uncommon (serious) adverse events were observed in either treatment arm. Analyses of secondary outcomes showed that patients in both groups reported similar significant reductions in their gout symptoms. CONCLUSION: Efficacy of anakinra was shown to be non-inferior to treatment as usual for the treatment of acute gout flares, suggesting that anakinra is an effective treatment alternative for acute gout flares. TRIAL REGISTRATION: Het Nederlands Trial Register, www.trialregister.nl, NTR5234.

International Consortium for Health Outcome Measurement Set of Outcomes That Matter to People Living With Inflammatory Arthritis: Consensus From an International Working Group.

OBJECTIVE: The implementation of value-based health care in inflammatory arthritis requires a standardized set of modifiable outcomes and risk-adjustment variables that is feasible to implement worldwide. METHODS: The International Consortium for Health Outcomes Measurement (ICHOM) assembled a multidisciplinary working group that consisted of 24 experts from 6 continents, including 6 patient representatives, to develop a standard set of outcomes for inflammatory arthritis. The process followed a structured approach, using a modified Delphi process to reach consensus on the following decision areas: conditions covered by the set, outcome domains, outcome measures, and risk-adjustment variables. Consensus in areas 2 to 4 were supported by systematic literature reviews and consultation of experts. RESULTS: The ICHOM Inflammatory Arthritis Standard Set covers patients with rheumatoid arthritis (RA), axial spondyloarthritis, psoriatic arthritis, and juvenile idiopathic arthritis (JIA). We recommend that outcomes regarding pain, fatigue, activity limitations, overall physical and mental health impact, work/school/housework ability and productivity, disease activity, and serious adverse events be collected at least annually. Validated measures for patient-reported outcomes were endorsed and linked to common reporting metrics. Age, sex at birth, education level, smoking status, comorbidities, time since diagnosis, and rheumatoid factor and anti-citrullinated protein antibody lab testing for RA and JIA should be collected as risk-adjustment variables. CONCLUSION: We present the ICHOM inflammatory arthritis Standard Set of outcomes, which enables health care providers to implement the value-based health care framework and compare outcomes that are important to patients with inflammatory arthritis.

Rasch measurement in rheumatoid arthritis: deriving psychometrically optimal measures from the Rasch Everyday Activity Limitation item bank.

Objective: Recently we developed the Rasch Everyday Activity Limitations (REAL) generic item bank for measuring physical function. In this study we evaluate the REAL item bank in 209 RA patients and demonstrate how computerized adaptive testing (CAT) and Optimal Test Assembly methods can be used to derive measures from the REAL item bank with superior measurement performance compared with the HAQ Disability Index (HAQ-DI). Methods: Structural validity of the item bank was assessed using confirmatory factor analysis. The validity of the REAL score metric in RA was evaluated by examining differential item functioning against the general population calibration sample. Besides the REAL-CAT, a 6-item short form (REAL-6) was developed using Optimal Test Assembly that was optimized with respect to common disability levels in RA, content and reading ease. Measurement precision of the different instruments was examined using item response theory methods. Construct validity was evaluated by testing hypothesized correlations with external measures. Results: Good model-data fit was observed for a one-dimensional model and only two items showed differential item functioning of substantial magnitude. The REAL-CAT had superior measurement precision compared with HAQ-DI and REAL-6. REAL-6 outperformed HAQ-DI across all but the very lowest level of physical function. All three instruments demonstrated good construct validity (>75% of hypotheses affirmed) and only HAQ-DI had a ceiling effect (23.9%). Conclusion: This study supports the validity of the REAL item bank and illustrates the potential of CAT and OTA applications based on the REAL item bank for assessing physical function in RA.

An Economic Evaluation of Stopping Versus Continuing Tumor Necrosis Factor Inhibitor Treatment in Rheumatoid Arthritis Patients With Disease Remission or Low Disease Activity: Results From a Pragmatic Open-Label Trial.

OBJECTIVE: To evaluate, from a societal perspective, the incremental cost-effectiveness of withdrawing tumor necrosis factor inhibitor (TNFi) treatment compared to continuation of these drugs within a 1-year, randomized trial among rheumatoid arthritis patients with longstanding, stable disease activity or remission. METHODS: Data were collected from a pragmatic, open-label trial. Cost-utility analysis was performed using the nonparametric bootstrapping method, and a cost-effectiveness acceptability curve was constructed using the net-monetary benefit framework, where a willingness-to-accept threshold (WTA) was defined as the minimal cost saved that a patient accepted for each quality-adjusted life year (QALY) lost. RESULTS: A total of 531 patients were randomized to the stop group and 286 patients to the continuation group. Withdrawal of TNFi treatment resulted in a >60% reduction of the total drug cost, but led to an increase of ∼30% in other health care expenditures. Compared to continuation, stopping TNFi resulted in a mean yearly cost saving of €7,133 (95% confidence interval [95% CI] €6,071, €8,234]) and was associated with a mean loss of QALYs of 0.02 (95% CI 0.002, 0.040). Mean saved cost per QALY lost and per extra flare incurred in the stop group compared to the continuation group was €368,269 (95% CI €155,132, €1,675,909) and €17,670 (95% CI €13,650, €22,721), respectively. At a WTA of €98,438 per QALY lost, the probability that stopping TNFi treatment is cost-effective was 100%. CONCLUSION: Although an official WTA is not defined, the mean saved cost of €368,269 per QALY lost seems acceptable in The Netherlands, given existing data on willingness to pay.

Development of an item bank to measure factual disease and treatment related knowledge of rheumatoid arthritis patients in the treat to target era.

OBJECTIVE: To develop a Disease and treatment associated Knowledge in RA item bank (DataK-RA) based on item response theory. METHODS: Initial items were developed from a systematic review. Rheumatology professionals identified relevant content trough a RAND modified Delphi scoring procedure and consensus meeting. RA patients provided additional content trough a focus group. Patients and professionals rated readability, feasibility and comprehensiveness of resulting items. Cross-sectional data were collected to evaluate psychometric properties of the items. RESULTS: Data of 473 patients were used for item reduction and calibration. Twenty items were discarded based on corrected item-total point biserial correlation <0.30. Confirmatory factor analysis with weighted least squares estimation on the polychoric correlation matrix suggested good fit for a unidimensional model for the remaining 42 items (CFI 0.97 TLI=0.97, RMSEA=0.02, WRMR=0.97), supporting the proposed scoring procedure. Scores were highly reliable and normally distributed with minimal ceiling (1.8%) and no floor effects. 75% of tested hypotheses about the association of DataK-RA scores with related constructs were supported, indicating good construct validity. CONCLUSION: DataK-RA is a psychometrically sound item bank. PRACTICE IMPLICATIONS: DataK-RA provides health professionals and researchers with a tool to identify and target patients' information needs or to assess effects of educational efforts.

Quality of care in gout: a clinical audit on treating to the target with urate lowering therapy in real-world gout patients.

The current paper aimed to describe the quality of care for gout patients by showing the clinical outcomes achieved in two patient cohorts in which differing targeted urate lowering therapy (ULT) treatment approaches were employed, both aiming to reach the European League Against Rheumatism recommended serum urate (sUA) targets. A retrospective medical chart review study was conducted. Data from the medical records of gout patients from two clinical centers in The Netherlands, both applying targeted ULT treatments (albeit using different approaches), were reviewed. Patients in cohort A were given a combination of xanthine oxidase inhibitors with uricosurics if treatment with allopurinol monotherapy failed to reach sUA target levels, whereas patients in cohort B were treated with sequential monotherapy. Data on patient characteristics and clinical outcomes were collected. A total of 177 patient dossiers were included: 99 from cohort A and 78 from cohort B. The great majority (n = 146, 82.5%) of the patients in both cohorts had a current sUA level <360 µmol/L. In addition, more than half (n = 104, 58.8%) of the patients met the stringent sUA target level of <300 µmol/L. The largest reductions in mean sUA levels were observed for patients who were treated with combination therapy. This clinical audit of two cohorts of gout patients provides initial-yet promising-results regarding the proportion of real-world gout patients in whom recommended that sUA target levels can be achieved, and demonstrates the added value that a targeted treatment approach may have in reaching these goals.

Measuring everyday functional competence using the Rasch assessment of everyday activity limitations (REAL) item bank.

OBJECTIVE: Traditional patient-reported physical function instruments often poorly differentiate patients with mild-to-moderate disability. We describe the development and psychometric evaluation of a generic item bank for measuring everyday activity limitations in outpatient populations. STUDY DESIGN AND SETTING: Seventy-two items generated from patient interviews and mapped to the International Classification of Functioning, Disability and Health (ICF) domestic life chapter were administered to 1128 adults representative of the Dutch population. The partial credit model was fitted to the item responses and evaluated with respect to its assumptions, model fit, and differential item functioning (DIF). Measurement performance of a computerized adaptive testing (CAT) algorithm was compared with the SF-36 physical functioning scale (PF-10). RESULTS: A final bank of 41 items was developed. All items demonstrated acceptable fit to the partial credit model and measurement invariance across age, sex, and educational level. Five- and ten-item CAT simulations were shown to have high measurement precision, which exceeded that of SF-36 physical functioning scale across the physical function continuum. Floor effects were absent for a 10-item empirical CAT simulation, and ceiling effects were low (13.5%) compared with SF-36 physical functioning (38.1%). CAT also discriminated better than SF-36 physical functioning between age groups, number of chronic conditions, and respondents with or without rheumatic conditions. CONCLUSION: The Rasch assessment of everyday activity limitations (REAL) item bank will hopefully prove a useful instrument for assessing everyday activity limitations. T-scores obtained using derived measures can be used to benchmark physical function outcomes against the general Dutch adult population.

Further Simplification of the Simple Erosion Narrowing Score With Item Response Theory Methodology.

OBJECTIVE: To further simplify the simple erosion narrowing score (SENS) by removing scored areas that contribute the least to its measurement precision according to analysis based on item response theory (IRT) and to compare the measurement performance of the simplified version to the original. METHODS: Baseline and 18-month data of the Combinatietherapie Bij Reumatoide Artritis (COBRA) trial were modeled using longitudinal IRT methodology. Measurement precision was evaluated across different levels of structural damage. SENS was further simplified by omitting the least reliably scored areas. Discriminant validity of SENS and its simplification were studied by comparing their ability to differentiate between the COBRA and sulfasalazine arms. Responsiveness was studied by comparing standardized change scores between versions. RESULTS: SENS data showed good fit to the IRT model. Carpal and feet joints contributed the least statistical information to both erosion and joint space narrowing scores. Omitting the joints of the foot reduced measurement precision for the erosion score in cases with below-average levels of structural damage (relative efficiency compared with the original version ranged 35-59%). Omitting the carpal joints had minimal effect on precision (relative efficiency range 77-88%). Responsiveness of a simplified SENS without carpal joints closely approximated the original version (i.e., all Δ standardized change scores were ≤0.06). Discriminant validity was also similar between versions for both the erosion score (relative efficiency = 97%) and the SENS total score (relative efficiency = 84%). CONCLUSION: Our results show that the carpal joints may be omitted from the SENS without notable repercussion for its measurement performance.