Organ involvement and assessment in sarcoidosis.

PURPOSE OF REVIEW: In recent years new recommendations have been published about organ assessment in the diagnosis of sarcoidosis. RECENT FINDINGS: Screening for pulmonary, cardiac, ocular, neurologic and renal involvement and hypercalcemia is recommended in the work-up for sarcoidosis, additionally, screening for hypercalciuria at the time of the diagnosis might be beneficial. SUMMARY: One of the goals in the work-up of sarcoidosis is to assess the extent and severity of organ involvement. Timely and accurate assessment leads to determination of treatment indication. Screening for pulmonary involvement should include pulmonary imaging and pulmonary function tests. Screening for cardiac involvement should include a clear history including palpitations and collapse and a baseline electrocardiogram or 24-h Holter monitoring. At diagnosis, ophthalmological assessment is recommended. Furthermore, serum calcium level and serum creatinine level should be obtained. Although routine 24-h urinary calcium excretion is not included in the guidelines, performing this test routinely can be considered. On indication, neurologic, rheumatologic or dermatologic assessment can be performed.

The added value of predictive biomarkers in treat-to-target strategies for rheumatoid arthritis patients: a conceptual modelling study.

OBJECTIVES: To quantify the additional value of a hypothetical biomarker predicting response to treatment for RA regarding efficacy and costs by using a modelling design. METHODS: A Markov model was built comparing a usual care T2T strategy with a biomarker-steered strategy for RA patients starting biologic therapy. Outcome measures include time spent in remission or low disease activity (LDA) and costs. Four additional scenario analyses were performed by varying biomarker or clinical care characteristics: (i) costs of the biomarker; (ii) sensitivity and specificity of the biomarker; (iii) proportion of eligible patients tapering; and (iv) medication costs. RESULTS: In the base model, patients spent 2.9 months extra in LDA or remission in the biomarker strategy compared with usual care T2T over 48 months. Total costs were €43 301 and €42 568 for, respectively, the usual care and biomarker strategy, and treatment costs accounted for 91% of total costs in both scenarios. Cost savings were driven due to patients in the biomarker strategy experiencing remission or LDA earlier, and starting tapering sooner. Cost-effectiveness was not so much driven by costs or test characteristics of the biomarker (scenario 1/2), but rather by the level of early and proactive tapering and drug costs (scenarios 3/4). CONCLUSIONS: The use of a biomarker for prediction of response to b/tsDMARD treatment in RA can be of added value to current treat-to-target clinical care. However, gains in efficacy are modest and cost gains are depending on a combination of early proactive tapering and high medication costs.

Determinants of the Physician Global Assessment of Disease Activity and Influence of Contextual Factors in Early Axial Spondyloarthritis.

OBJECTIVE: To investigate determinants of the physician global assessment (PhGA) of disease activity and the influence of the contextual factors on this relationship in patients with early axial spondyloarthritis (SpA). METHODS: Five-year data of DESIR, a cohort of early axial SpA, were analyzed. Univariable generalized estimating equations (GEEs) were used to investigate contributory explanatory effects of various potential determinants of PhGA. Effect modification by contextual factors (age, sex, and educational level) was tested, and if significant, models were stratified. Autoregressive GEE models (i.e., models adjusted for PhGA at the previous time point) were used to confirm a longitudinal relationship. RESULTS: A total of 708 patients were included. Higher Bath Ankylosing Spondylitis Disease Activity Index individual questions, swollen joint count in 28 joints (SJC28), tender joint count in 53 joints, Maastricht Ankylosing Spondylitis Enthesitis Score, C-reactive protein (CRP) level, and Bath Ankylosing Spondylitis Metrology Index score were associated with a higher PhGA. Sex and age were effect modifiers of SJC28; the contributory effect of SJC28 was largest in the younger male stratum (ß = 1.07 [95% confidence interval (95% CI) 0.71, 1.43]), and the smallest in the older female stratum (ß = 0.13 [95% CI 0.04, 0.22]). Autoregressive GEE models revealed the same determinants as having a longitudinal association with PhGA and the same pattern of effect modification. CONCLUSION: Patients' subjective symptoms, peripheral arthritis and enthesitis, higher CRP level, and impaired spinal mobility contribute to explaining PhGA in patients with early axial SpA, irrespective of sex and age. Intriguingly, physicians consider the presence of swollen joints as more important in males than in females.

Assessment of radiographic progression in patients with rheumatoid arthritis treated with tofacitinib in long-term studies.

OBJECTIVES: Tofacitinib is an oral Janus kinase inhibitor for the treatment of RA. We evaluated radiographic progression in tofacitinib-treated patients with RA for up to 3 years in two pooled long-term extension (LTE) studies (ORAL Sequel; A3921041) (primary analysis), and for up to 5 years using data integrated from one phase (P)2 (A3921068), two P3 (ORAL Start; ORAL Scan) and two LTE studies (exploratory analysis). METHODS: In LTE studies, patients received tofacitinib 5 mg twice daily (BID) or 10 mg BID as monotherapy or with conventional synthetic (cs)DMARDs. Radiographic outcomes up to 3 years: least squares mean (LSM) change from baseline in van der Heijde modified Total Sharp Score (ΔmTSS), erosion score (ΔES) and joint space narrowing (ΔJSN) score; proportion of patients with no radiographic progression (ΔmTSS ≤0.5); proportion of patients with no new erosions (ΔES ≤0.5). ΔmTSS was evaluated for up to 5 years in an exploratory analysis. RESULTS: For all tofacitinib-treated patients with radiographic data available at LTE month 36 (n = 414), LSM ΔmTSS was 1.14, LSM ΔES was 0.66, LSM ΔJSN was 0.74, and 74.3% and 86.2% of patients showed no radiographic progression and no new erosions, respectively. Similar values were observed regardless of tofacitinib dose, or whether patients received tofacitinib as monotherapy or with csDMARDs. In an exploratory analysis of integrated P2/P3/LTE studies, LSM ΔmTSS was 3.34 at month 60 (n = 269). CONCLUSION: Limited progression of structural damage was observed in tofacitinib-treated patients up to 5 years, with similar results for tofacitinib used as monotherapy or combination therapy up to 3 years. TRIAL REGISTRATION: ClinicalTrials.gov (http://clinicaltrials.gov): NCT01164579; NCT01039688; NCT00847613; NCT00413699; NCT00661661.

Development and validation of an alternative ankylosing spondylitis disease activity score when patient global assessment is unavailable.

OBJECTIVE: To develop an alternative Ankylosing Spondylitis Disease Activity Score (ASDAS) to be used in research settings in axial SpA (axSpA) when Patient Global Assessment (PGA) is unavailable in databases. METHODS: Longitudinal data from four axSpA cohorts and two randomized controlled trials were combined. Observations were randomly split in a development (N = 1026) and a validation cohort (N = 1059). Substitutes of PGA by BASDAI total score, single or combined individual BASDAI questions, and a constant value, were established in the development cohort. Conversion factors for each substitute were defined by Generalized Estimating Equations, obtaining seven 'alternative' formulae. Validation was performed in the validation cohort according to the OMERACT filter, taking into consideration: (i) truth (agreement with original-ASDAS in the continuous score, by intraclass correlation coefficient and in disease activity states, by weighted kappa); (ii) discrimination [standardized mean difference of ASDAS scores between high/low disease activity states defined by external anchors, e.g. Patient Acceptable Symptom State; agreement (kappa) in the percentage of patients reaching ASDAS improvement criteria according to alternative vs original formulae]; and (iii) feasibility. RESULTS: Comparing various options, alternative-ASDAS using BASDAI total as PGA replacement proved to be: truthful (intraclass correlation coefficient = 0.98, kappa = 0.90), discriminative [ASDAS scores between Patient Acceptable Symptom State no/yes: standardized mean difference = 1.37 (original-ASDAS standardized mean difference = 1.43); agreement with original-ASDAS in major improvement/clinically important improvement criteria: kappa = 0.93/0.88] and feasible (BASDAI total often available, as questions required for the ASDAS; conversion coefficient ≈ 1). CONCLUSION: Alternative-ASDAS using BASDAI total score as PGA replacement is the most truthful, discriminative and feasible instrument.

Determinants of the patient global assessment of well-being in early axial spondyloarthritis: 5-year longitudinal data from the DESIR cohort.

OBJECTIVES: To investigate the determinants of patient well-being over time, and the influence of age, gender and education in patients with early axial spondyloarthritis (axSpA). METHODS: Five-year data from DESIR, a cohort of early axSpA, were analysed. The outcome was the BAS-G over 5 years. Generalized estimating equations (GEE) were used to test the relationship between potential explanatory variables from five outcome domains (disease activity, physical function, spinal mobility, structural damage and axial inflammation) and BAS-G over time. Longitudinal relationships were analysed using an autoregressive GEE model. Age, gender and educational level were tested as effect modifiers or confounders. RESULTS: A total of 708 patients were included. Higher BASDAI questions on fatigue [ß (95% CI): 0.17 (0.13, 0.22)], back pain [0.51 (0.46, 0.56)], peripheral joint pain [0.08 (0.04, 0.12)] and severity of morning stiffness [0.08 (0.03-0.13)], and higher BASFI [0.14 (0.08, 0.19)] were associated with a higher BAS-G. In the autoregressive model, the same variables except for morning stiffness were associated with a worsening in BAS-G. Age, gender and educational level were neither effect modifiers nor confounders. CONCLUSION: A higher level of back pain is associated with a worsening of patient well-being, as are, though to a lesser extent, higher levels of fatigue, peripheral joint pain and physical disability. Age, gender and educational level do not have an impact on these relationships.

EULAR recommendations for the management of rheumatoid arthritis with synthetic and biological disease-modifying antirheumatic drugs: 2019 update.

OBJECTIVES: To provide an update of the European League Against Rheumatism (EULAR) rheumatoid arthritis (RA) management recommendations to account for the most recent developments in the field. METHODS: An international task force considered new evidence supporting or contradicting previous recommendations and novel therapies and strategic insights based on two systematic literature searches on efficacy and safety of disease-modifying antirheumatic drugs (DMARDs) since the last update (2016) until 2019. A predefined voting process was applied, current levels of evidence and strengths of recommendation were assigned and participants ultimately voted independently on their level of agreement with each of the items. RESULTS: The task force agreed on 5 overarching principles and 12 recommendations concerning use of conventional synthetic (cs) DMARDs (methotrexate (MTX), leflunomide, sulfasalazine); glucocorticoids (GCs); biological (b) DMARDs (tumour necrosis factor inhibitors (adalimumab, certolizumab pegol, etanercept, golimumab, infliximab), abatacept, rituximab, tocilizumab, sarilumab and biosimilar (bs) DMARDs) and targeted synthetic (ts) DMARDs (the Janus kinase (JAK) inhibitors tofacitinib, baricitinib, filgotinib, upadacitinib). Guidance on monotherapy, combination therapy, treatment strategies (treat-to-target) and tapering on sustained clinical remission is provided. Cost and sequencing of b/tsDMARDs are addressed. Initially, MTX plus GCs and upon insufficient response to this therapy within 3 to 6 months, stratification according to risk factors is recommended. With poor prognostic factors (presence of autoantibodies, high disease activity, early erosions or failure of two csDMARDs), any bDMARD or JAK inhibitor should be added to the csDMARD. If this fails, any other bDMARD (from another or the same class) or tsDMARD is recommended. On sustained remission, DMARDs may be tapered, but not be stopped. Levels of evidence and levels of agreement were mostly high. CONCLUSIONS: These updated EULAR recommendations provide consensus on the management of RA with respect to benefit, safety, preferences and cost.

Individual-level and country-level socioeconomic determinants of disease outcomes in SpA: multinational, cross-sectional study (ASAS-COMOSPA).

OBJECTIVE: To explore the independent contribution of individual-level and country level socioeconomic status (SES) determinants to disease activity and physical function in patients with spondyloarthritis (SpA). METHODS: Data from the cross-sectional, multinational (n=22 countries worldwide) COMOSPA (COMOrbidities in SpA) study were used. Contribution of individual SES factors (gender, education) and country of residence to Ankylosing Spondylitis Disease Activity Score (ASDAS) and Bath Ankylosing Spondylitis Functional Index (BASFI) was explored in multilevel regression models, adjusting for clinical and demographic confounders. Next, the additional effects of national macroeconomic indicators (gross domestic product [GDP], Human Development Index, healthcare expenditure and Gini index) were explored. The mediating role of uptake of biologic disease-modifying antirheumatic drugs between education or GDP and ASDAS was explored by testing indirect effects. RESULTS: In total, 3370 patients with SpA were included: 65% were male, with a mean age of 43 (SD 14), ASDAS of 2.0 (SD 1.1) and BASFI score of 3.1 (SD 2.7). In adjusted models, patients with low education and female patients had an OR of 1.7 (95% CI 1.3 to 2.2) and an OR of 1.7 (95% CI 1.4 to 2.0), respectively, of having ASDAS ≥2.1. They also reported slightly worse function. Large country differences were observed independent of individual SES and clinical confounders. Patients from less SES developed countries have worse ASDAS, while patterns for BASFI were insignificant. Uptake of biologicals did not mediate the relationship between individual-level or country-level SES and disease activity. CONCLUSIONS: Individual-level and country-level health inequalities exist also among patients with SpA. Women and lower educated persons had worse disease activity and somewhat worse physical function. While patients in less socioeconomically developed countries had higher disease activity, they reported similar physical function.

Routine Assessment of Patient Index Data 3 (RAPID3) alone is insufficient to monitor disease activity in rheumatoid arthritis in clinical practice.

Objective: To test the longitudinal association between patient-reported outcome, Routine Assessment of Patient Index Data 3 (RAPID3) and the Disease Activity Score in 28 joints that includes the erythrocyte sedimentation rate (DAS28-ESR) in routine-care patients with rheumatoid arthritis (RA). Methods: Patients with RA treated with disease-modifying antirheumatic drugs were included in this prospective observational cohort. The longitudinal association between RAPID3 (0-10) and DAS28-ESR and its individual components (swollen joint count (SJC), erythrocyte sedimentation rate (ESR) (mm/hour), tender joint count (TJC) and patient global assessment (PGA)) was tested using generalised estimating equations in patients with more than two consecutive visits with data on RAPID3 and DAS28-ESR. Interactions between RAPID3 and gender, pain, PGA and age at baseline were tested, and if significant (p<0.20) and clinically relevant, models were fit in the corresponding strata. Results: In total, 330 patients were included (mean follow-up 10.7 (SD 9.7) months, female gender 67.9%). The longitudinal association between RAPID3 and DAS28-ESR was weak (ß=0.29 (95% CI 0.24 to 0.35), n=207), meaning that one unit increase in RAPID3 corresponded to a 0.29 unit increase in Disease Activity Score in 28 joints (DAS28). RAPID3 was most strongly associated with subjective (TJC: ß=0.89 (95% CI 0.61 to 1.17); PGA: ß=0.94 (95% CI 0.84 to 1.04)) and not with objective components of DAS28 (SJC: ß=0.29 (95% CI 0.17 to 0.41), n=172). The association between RAPID3 and ESR was poor but modified by gender, being only significant in men (ß=0.37 (95% CI 0.08 to 0.67)). Conclusions: These data suggest that RAPID3 does not sufficiently capture changes in objective inflammatory signs. Monitoring by RAPID3 alone is therefore insufficient to follow disease activity in patients wth RA in clinical practice.

Inequity in access to bDMARD care and how it influences disease outcomes across countries worldwide: results from the METEOR-registry.

OBJECTIVE: To establish in a global setting the relationships between countries' socioeconomic status (SES), measured biological disease modifying antirheumatic drug (bDMARD)-usage and disease outcomes. To assess if prescription and reimbursement rules and generic access to medication relates to a countries' bDMARD-usage. METHODS: Data on disease activity and drug use from countries that had contributed at least 100 patients were extracted from the METEOR database. Mean disease outcomes of all available patients at the final visit were calculated on a per-country basis. A questionnaire was sent to at least two rheumatologists per country inquiring about DMARD-prices, access to treatment and valid regulations for prescription and reimbursement. RESULTS: Data from 20 379 patients living in 12 different countries showed that countries' SES was positively associated with measured disease activity (meanDAS28), but not always with physical functioning (HAQ-score). A lower country's SES, stricter rules for prescription and reimbursement of bDMARDs as well as worse affordability of bDMARDs were associated with lower bDMARD-usage. bDMARD-usage was negatively associated with disease activity (although not with physical functioning), but the association was moderate at best. CONCLUSIONS: Disease activity in patients with rheumatoid arthritis as well as bDMARD-usage varies across countries worldwide. The (negative) relationship between countries' bDMARD-usage and level of disease activity is complex and under the influence of many factors, including-but not limited to-countries' SES, affordability of bDMARDs and valid prescription and reimbursement rules for bDMARDs.

An Assessment in SpondyloArthritis International Society (ASAS)-endorsed definition of clinically important worsening in axial spondyloarthritis based on ASDAS.

INTRODUCTION: In a previous phase, 12 draft definitions for clinically important worsening in axial spondyloarthritis (axSpA) were selected, of which 3 were based on absolute changes in Ankylosing Spondylitis Disease Activity Score (ASDAS)-CRP (ASDAS). The objective here was to select the best cut-off for ASDAS for clinically important worsening in axSpA for use in clinical trials and observational studies. METHODS: An international longitudinal prospective study evaluating stable patients with axSpA was conducted. Data necessary to calculate ASDAS were collected at two consecutive visits (spaced 7 days to 6 months). Sensitivity and specificity of the three cut-offs for change in ASDAS were tested against the patient's subjective assessment of worsening as the external standard (ie, the patient reporting that he had worsened and felt a need for treatment intensification). Final selection was made by a consensus and voting procedure among Assessment of SpondyloArthritis International Society (ASAS) members. RESULTS: In total, 1169 patients with axSpA were analysed: 64.8% were male and had a mean age of 41.7 (SD 12.4) years. At the second visit, 127 (10.9%) patients judged their situation as worsened.Sensitivity and specificity for an increase of at least 0.6, 0.9 and 1.1 ASDAS points to detect patient-reported worsening were 0.55 (Se) and 0.91 (Sp), 0.38 (Se) and 0.96 (Sp), and 0.33 (Se) and 0.98 (Sp), respectively. The ASAS consensus was to define clinically important worsening as an increase in ASDAS of at least 0.9 points. CONCLUSION: This data-driven ASAS consensus process resulted in an ASDAS-based cut-off value defining clinically important worsening in axSpA for use in trials.

Impact of Stopping Tumor Necrosis Factor Inhibitors on Rheumatoid Arthritis Patients' Burden of Disease.

OBJECTIVE: To determine the impact of stopping tumor necrosis factor inhibitor (TNFi) treatment on patient-reported outcomes (PROs) of physical and mental health status, health utility, pain, disability, and fatigue in patients with established rheumatoid arthritis (RA). METHODS: In the pragmatic, 12-month POET trial, 817 RA patients with ≥6 months of remission or stable low disease activity were randomized 2:1 to stopping or continuing TNFi. In case of flare, TNFi was restarted at the discretion of the rheumatologist. PROs were assessed every 3 months. RESULTS: TNFi was restarted within 12 months in 252 of 531 patients (47.5%) in the stop group. At 3 months, mean PRO scores were significantly worse in the stop group, and a larger proportion of patients experienced a minimum clinically important difference (MCID) on all PROs. Effect sizes (ES) were strongest for health utility (ES -0.24) and pain (ES -0.30). Mean scores improved again after this point, but disability scores remained significantly different at 12 months. After 12 months, the relative risk of experiencing an MCID ranged from 1.16 for mental health status to 1.58 for fatigue. Mean PRO scores for patients restarting TNFi within 6 months were no longer significantly different from those that did not restart TNFi at 12 months. CONCLUSION: Stopping TNFi had a significant negative short-term impact on a broad range of PROs. Long-term negative consequences appeared to be limited, and outcomes in patients needing to restart TNFi within the first 6 months tended to be restored at 12 months.

Can we improve the performance and reporting of investigator-initiated clinical trials? Rheumatoid arthritis as an example.

Investigator-initiated trials, some of which have been referred to as comparative effectiveness trials, pragmatic trials, or strategy trials, are sometimes considered to be of greater clinical importance than industry-driven trials, because they address important but unresolved clinical questions that differ from the questions asked in industry-driven trials. Regulatory authorities have provided methodological guidance for industry-driven trials for the approval of new treatments, but such guidance is less clear for investigator-initiated trials. The European League Against Rheumatism (EULAR) task force for the update of the recommendations for the management of rheumatoid arthritis has critically looked at the methodological quality and conduct of many investigator-initiated trials, and has identified a number of concerns. In this Viewpoint paper, we highlight commonly encountered issues that are discussed using examples of well-known investigator-initiated trials. These issues cover three themes: (1) design choice (superiority vs non-inferiority designs); (2) statistical power and (3) convenience reporting. Since we acknowledge the importance of investigator-initiated research, we also propose a shortlist of points-to-consider when designing, performing and reporting investigator-initiated trials.

Assessment of global disease activity in RA patients monitored in the METEOR database: the patient's versus the rheumatologist's opinion.

The objectives of this study were to compare the patient's (PtGDA) and physician's (PhGDA) assessment of global disease activity and to identify factors that might influence these differences as well as factors that may influence the patient's and the physician's scores separately. Anonymous data were used from 2,117 Dutch patients included in the Measurement of efficacy of Treatment in the Era of Rheumatology database. PtGDA and PhGDA were scored independently on a 100-mm visual analog scale (VAS) with 0 and 100 as extremes. The agreement, intraclass correlation coefficients (ICC), was calculated and a Bland-Altman plot was created to visualize the differences between PtGDA and PhGDA. Linear mixed model analysis was used to model PtGDA and PhGDA. Logistic repeated measurements were used to model the difference in PtGDA and PhGDA (PtGDA > PhGDA versus PtGDA ≤ PhGDA). Gender patient, gender physician, age, swollen joint count (SJC), tender joint count, VAS pain, disease duration, and erythrocyte sedimentation rate (ESR) were considered as possible determinants in both models. Mean (standard deviation) age was 57 (15) years and 67 % of the patients were female. Agreement between PtGDA and PhGDA was moderate (ICC, 0.57). Patients scored on average 11 units higher (worse) than rheumatologists (95 % limits of agreement, -25.2 to 47.6). Patient's perception of pain (VAS) was positively associated with a PtGDA being higher than PhGDA. Similarly, ESR and swollen joint counts were positively associated with a PtGDA being lower or equal to the PhGDA. Patients rate global disease activity consistently higher than their rheumatologists. Patients base their judgment primarily on the level of pain, physicians on the level of SJC and ESR.

Clinical assessment and outcome research in spondyloarthritis.

Spondyloarthritis (SpA; formerly called seronegative arthritis) generally follows a chronic course with an uncertain outcome and includes diseases, such as ankylosing spondylitis and psoriatic arthritis, that require regular medical care and monitoring to control for disease activity and maintain physical function. This article describes recent achievements in the field of clinical outcome assessment, imaging, and the classification of patients with SpA symptoms. Clinical instruments are addressed that measure function, disease activity, and pain through questionnaires, physical examination, and laboratory tests. Furthermore, the value of different imaging techniques for daily practice is described, and the new classification criteria for axial SpA are discussed.

International spondyloarthritis interobserver reliability exercise--the INSPIRE study: I. Assessment of spinal measures.

OBJECTIVE: To determine whether the axial measures used in primary ankylosing spondylitis (AS) were reproducible for both AS and psoriatic arthritis (PsA) with axial disease. METHODS: A group of 20 rheumatologists from 11 countries with expertise in spondyloarthritis (SpA) met for a combined physical examination exercise to assess 10 patients with PsA with axial involvement (9 men, 1 woman, mean age 52 yrs, mean disease duration 17 yrs) and 9 AS patients (7 men, 2 women, mean age 38 yrs, mean disease duration 16 yrs). A modified Latin-square design was used. Measures included were occiput to wall, tragus to wall, cervical rotation, chest expansion, lateral spinal bending, modified Schober, and hip mobility. Data were analyzed using intraclass correlation coefficients (ICC) adjusted for order of measurements. RESULTS: The majority of the variance was contributed by the patients. There was no order effect. Observer effect was noted especially for chest expansion for both AS and PsA patients, and for the modified Schober in PsA. The ICC demonstrated very good to excellent agreement for most measures for both AS and PsA. Chest expansion provided only moderate agreement for AS and PsA. CONCLUSION: Overall, measures of spinal mobility used in primary AS perform well with respect to interobserver reliability, and are equally reproducible when applied to PsA patients with axial involvement. Thus, these measures should now be evaluated in therapeutic trials of patients with PsA to determine sensitivity to change and concordance with other measures of structural damage.

International spondyloarthritis interobserver reliability exercise--the INSPIRE study: II. Assessment of peripheral joints, enthesitis, and dactylitis.

OBJECTIVE: To determine whether the assessments of peripheral joints and enthesitis were reproducible for both AS and PsA with axial disease, and whether dactylitis assessment is reproducible in patients with PsA. METHODS: A group of 20 rheumatologists from 11 countries with expertise in spondyloarthritis (SpA) met for a combined physical examination exercise to assess 10 patients with PsA with axial involvement (9 men, 1 woman, mean age 52 yrs, disease duration 17 yrs) and 9 patients with AS (7 men, 2 women, mean age 38 yrs, disease duration 16 yrs). A modified Latin-square design that enabled assessment of patient, assessor, and order effect was used. Measures included were number of tender and swollen joints, presence of enthesitis using 6 different indices, and dactylitis score. Data were analyzed using intraclass correlation (ICC) adjusted for order of measurements. RESULTS: The majority of the variance was contributed by the patients. There was no order effect. The assessment of tender joints (ICC 0.69) was more reliable than the assessment of swollen joints (ICC 0.54). Moreover, there was better agreement in patients with PsA (ICC 0.78) than in patients with AS (ICC 0.62). There was excellent agreement on the number of active enthesitis sites (ICC 0.86). All the enthesitis indices provided substantial to excellent agreement among observers. Agreement for the dactylitis score was substantial (ICC 0.70). CONCLUSION: The assessment of peripheral joints is more reliable in patients with PsA. Enthesitis instruments can be used reliably in patients with AS and patients with PsA with spinal involvement. The Leeds dactylitis instrument functions well in PsA.

Principles of assessment from a clinical perspective.

Physicians apply assessments every day in clinical practice. Common clinical practice is impossible without measurements and tests. Testing looks rather straightforward: a test result is either positive or negative. Unfortunately, this simplicity is not in keeping with truth. At the base of measuring and testing in clinical practice lies the assumption of uncertainty: we do not know whether a patient has a disease, we can only estimate the probability that he has a disease by performing a (chain of) test(s). Every test result leaves open the chance that a wrong decision is taken on the basis of the test result. It is a challenge for the clinician to get a better insight into this process, as well as to minimize the chance of wrong decisions. By using a number of clinical examples, we describe here the principles of assessment from two different perspectives: the perspective of the test, and the perspective of the individual patient. The former perspective incorporates test-specific characteristics, such as sensitivity, specificity, accuracy and cut-off levels, and the latter deals with individual probabilities from a 'Bayesian' concept.