Outcomes Measured in Polymyalgia Rheumatica and Measurement Properties of Instruments Considered for the OMERACT Core Outcome Set: A Systematic Review

Concordance and agreement between different activity scores in polymyalgia rheumatica

OBJECTIVE

The C reactive protein polymyalgia rheumatica activity score (CRP-PMR-AS) is a composite index that includes CRP levels and was developed specifically for PMR. As treatments such as interleukin-6 antagonists can normalise CRP levels, the erythrocyte sedimentation rate (ESR) of PMR-AS, the clinical (clin)-PMR-AS and the imputed-CRP (imp-CRP)-PMR-AS have been developed to avoid such bias. Our primary objective was to measure the correlation of these activity scores. Our secondary objective was to evaluate the concordance between different cutoffs of the PMR-ASs.

METHOD

Data from the Safety and Efficacy of tocilizumab versus Placebo in Polymyalgia rHeumatica With glucocORticoid dEpendence (SEMAPHORE) trial, a superiority randomised double-blind placebo-controlled trial, were subjected to post hoc analysis to compare the efficacy of tocilizumab versus placebo in patients with active PMR. The CRP-PMR-AS, ESR-PMR-AS, clin-PMR-AS and imp-CRP-PMR-AS were measured at every visit. The concordance and correlation between these scores were evaluated using kappa correlation coefficients, Bland-Altman correlations, intraclass correlation coefficients (ICCs) and scatter plots.

RESULTS

A total of 101 patients were included in the SEMAPHORE trial, and 100 were analysed in this study. The correlation between the PMR-ASs was excellent, as the ICC and kappa were >0.85 from week 4 until week 24 (CRP-PMR-AS ≤10 or >10). Bland-Altman plots revealed that the differences between the CRP-PMR-AS and the other threescores were low. The cut-off values for the clin-PMR-AS were similar to those for the CRP-PMR-AS 86% of the time.

CONCLUSION

The correlation between all the PMR-ASs was excellent, reflecting the low weight of CRP. In clinical trials using drugs that have an impact on CRP, the derived activity scores can be used.

TRIAL REGISTRATION NUMBER

NTC02908217.

Exploring the patient experience in polymyalgia rheumatica

Despite being the most common inflammatory rheumatic disease in the elderly (Partington et al., Ann Rheum Dis 77(12):1750-175, 2018), few studies to date have examined the patient experience of polymyalgia rheumatica (PMR). Our study explored patient perspectives in PMR by means of a survey and semi-structured group interviews. The results from this study highlight key aspects of the patient experience in PMR, including delays to diagnosis, complex attitudes toward glucocorticoid therapy, and a desire for alternate treatment strategies. Future trials should look to include physical function as a measured outcome. Finally, our results call attention to the chronicity of PMR symptoms, challenging the paradigm of PMR as a self-limiting condition.

Polymyalgia rheumatica

Polymyalgia rheumatica is an inflammatory disease producing pain and stiffness, mainly in the shoulders and pelvic girdle, in people older than 50 years. Elevation of acute phase reactants is common due to the inflammatory nature of the disease. Since there are no specific diagnostic tests, diagnosis requires the exclusion of other diseases with similar presentations. Imaging has helped to identify the pathological substrate of polymyalgia rheumatica and it is increasingly used to support clinical diagnosis or to detect coexistent giant cell arteritis. Although polymyalgia rheumatica does not clearly impair survival or organ function, it can have a detrimental effect on quality of life. Glucocorticoids at 12·5-25·0 mg prednisone per day are effective in inducing remission in most individuals but, when tapered, relapses occur in 40-60% of those affected and side-effects are common. Assessment of disease activity can be difficult because pain related to common comorbidities such as osteoarthritis and tendinopathies, can return when glucocorticoids are reduced, and acute phase reactants are increased less during flares in individuals undergoing treatment or might increase for other reasons. The role of imaging in assessing disease activity is not yet completely defined. In the search for more efficient and safer therapies, tocilizumab and sarilumab have shown efficacy in randomised controlled trials and additional targeted therapies are emerging. However, judicious risk-benefit balance is essential in applying therapeutic innovations to people with polymyalgia rheumatica.

Test-retest reliability of pain VAS/NRS, stiffness VAS/NRS, HAQ-DI and mHAQ in polymyalgia rheumatica: An OMERACT study

OBJECTIVE

To examine the test-retest reliability of four measurement instruments in polymyalgia rheumatica (PMR): pain severity visual analogue scale (VAS) / numerical rating score (NRS), stiffness severity VAS/NRS, the Health Assessment Questionnaire-Disability Index (HAQ-DI) and the modified Health Assessment Questionnaire (mHAQ).

METHOD

Two prospectively collected datasets were used. All participants had a diagnosis of PMR and only those with stable disease were included in analyses. Measurement instruments were administered twice, with a testing interval of two to six weeks. The intra-class correlation coefficient (ICC) was calculated using a two-way mixed effects model looking for absolute agreement. ICC values of 0.8-0.9 were deemed representative of good test-retest reliability, whilst values >0.9 were representative of excellent test-retest reliability.

RESULTS

From the first dataset, 38 participants were analysed. The ICC between baseline and 2 weeks for pain VAS, stiffness VAS, HAQ-DI and mHAQ were 0.84, 0.82, 0.92 and 0.92 respectively. From the second dataset, 58 participants were included in the analysis for pain NRS, 59 for stiffness NRS and 78 for mHAQ. The ICC between baseline and follow-up for pain NRS, stiffness NRS and mHAQ were 0.80, 0.83 and 0.87 respectively.

CONCLUSION

Pain severity VAS/NRS, stiffness severity VAS/NRS, HAQ-DI and mHAQ all demonstrate good to excellent test-retest reliability in a PMR patient population.

Development and psychometric evaluation of the PMR-Impact Scale: a new patient reported outcome measure for polymyalgia rheumatica

OBJECTIVES

PMR causes pain, stiffness and disability in older adults. Measuring the impact of the condition from the patient's perspective is vital to high-quality research and patient-centred care, yet there are no validated patient-reported outcome measures (PROMs) for PMR. We set out to develop and psychometrically evaluate a PMR-specific PROM.

METHODS

Two cross-sectional postal surveys of people with a confirmed diagnosis of PMR were used to provide data for field testing and psychometric evaluation. A total of 256 participants completed the draft PROM. Distribution of item responses was examined, and exploratory factor analysis and Rasch analysis were used to inform item reduction, formation of dimension structure and scoring system development. Some 179 participants completed the PROM at two time points, along with comparator questionnaires and anchor questions. Test-retest reliability, construct validity and responsiveness were evaluated.

RESULTS

Results from the field-testing study led to the formation of the PMR-Impact Scale (PMR-IS), comprising four domains (symptoms, function, psychological and emotional well-being, and steroid side effects). Construct validity and test-retest reliability met accepted quality criteria for each domain. There was insufficient evidence from this study to determine its ability to detect flares/deterioration, but the PMR-IS was responsive to improvements in the condition.

CONCLUSION

The PMR-IS offers researchers a new way to assess patient-reported outcomes in clinical studies of PMR. It has been developed robustly, with patient input at every stage. It has good construct validity and test-retest reliability. Further work is needed to fully establish its responsiveness and interpretability parameters, and to assess its real-world clinical utility.

Effect of Tocilizumab on Disease Activity in Patients With Active Polymyalgia Rheumatica Receiving Glucocorticoid Therapy: A Randomized Clinical Trial

IMPORTANCE

Few treatments are available for patients with glucocorticoid-dependent polymyalgia rheumatica. IL-6 antagonists may reduce disease activity in patients with active glucocorticoid-dependent polymyalgia rheumatica.

OBJECTIVE

To compare the efficacy of tocilizumab vs placebo in patients with glucocorticoid-dependent polymyalgia rheumatica.

DESIGN, SETTING, AND PARTICIPANTS

This double-blind, parallel-group, placebo-controlled randomized clinical trial enrolled 101 patients with polymyalgia rheumatica at 17 hospitals in France from February 2017 to October 2019. Final follow-up occurred in November 2020. Inclusion criteria were persistent disease activity (polymyalgia rheumatica activity score computed using the C-reactive protein level [CRP PMR-AS] >10) and prednisone dose greater than or equal to 10 mg per day.

INTERVENTIONS

Patients were randomly assigned to receive intravenous tocilizumab (8 mg/kg; n = 51) or placebo (n = 50) every 4 weeks for 24 weeks, combined with predefined standardized tapering of oral prednisone.

MAIN OUTCOMES AND MEASURES

The primary efficacy end point was CRP PMR-AS less than 10 (range, 0-100; higher values indicate greater activity; no minimal clinically important difference defined) combined with either prednisone dose less than or equal to 5 mg per day or a decrease in prednisone dose greater than or equal to 10 mg from baseline at week 24. There were 11 secondary outcomes assessed at week 24 included in this report, including disease activity (measured by CRP PMR-AS) and the proportion of patients no longer taking prednisone.

RESULTS

Of the 101 randomized patients (mean age, 67.2 years; 68 [67.3%] women), 100 (99%) received at least 1 infusion and 100 completed the trial. The primary end point was achieved in 67.3% of patients in the tocilizumab group and 31.4% of patients in the placebo group (adjusted difference, 36.0% [95% CI, 19.4%-52.6%]; adjusted relative risk, 2.3 [95% CI, 1.5-3.6]; P < .001). Of 11 reported secondary end points at 24 weeks, 7 showed significant differences favoring tocilizumab, including mean CRP PMR-AS score (7.5 [95% CI, 5.4-9.6] vs 14.9 [95% CI, 11.4-18.4]; adjusted difference, -7.5 [95% CI, -11.2 to -3.8]; P < .001) and the percentage of patients no longer receiving prednisone (49.0% vs 19.6%; adjusted difference, 29.3% [95% CI, 18.9%-39.7%]; adjusted relative risk, 2.5 [95% CI, 1.8-3.5]; P < .001). The most frequent adverse events were infections, experienced by 23 patients (46.9%) in the tocilizumab group and 20 (39.2%) in the placebo group.

CONCLUSIONS AND RELEVANCE

Among patients with active polymyalgia rheumatica despite prednisone therapy, tocilizumab, compared with placebo, resulted in a significantly greater percentage of patients with a CRP PMR-AS less than 10 with reduced prednisone requirements at week 24. Further research is needed to confirm efficacy and to determine the balance of potential benefits and harms.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02908217.

(Dis)agreement of polymyalgia rheumatica relapse criteria, and prediction of relapse in a retrospective cohort

Background

To develop and assess a prediction model for polymyalgia rheumatica (PMR) relapse within the first year of glucocorticoid (GC) treatment.

Methods

A retrospective PMR cohort (clinical diagnosis) from a rheumatology department was used. All visits > 30 days after starting GC treatment and with > 2.5 mg/day oral prednisolone were used as potential relapse visits. Often used relapse criteria (1) rheumatologist judgement, (2) treatment intensification-based relapse) were assessed for agreement in this cohort. The proportion of patients with treatment-based relapse within 1 and 2 years of treatment and the relapse incidence rate were used to assess unadjusted associations with candidate predictors using logistic and Poisson regression respectively. After using a multiple imputation method, a multivariable model was developed and assessed to predict the occurrence (yes/no) of relapse within the first year of treatment.

Results

Data from 417 patients was used. Relapse occurred at 399 and 321 (of 2422) visits based on the rheumatologist judgement- and treatment-based criteria respectively, with low to moderate agreement between the two (87% (95% CI 0.86–0.88), with κ = 0.49 (95% CI 0.44–0.54)). Treatment-based relapse within the first two years was significantly associated with CRP, ESR, and pre-treatment symptom duration, and incidence rate with only CRP and ESR. A model to predict treatment intensification within the first year of treatment was developed using sex, medical history of cardiovascular disease and malignancies, pre-treatment symptom duration, ESR, and Hb, with an AUC of 0.60–0.65.

Conclusion

PMR relapse occurs frequently, although commonly used criteria only show moderate agreement, underlining the importance of a uniform definition and criteria of a PMR specific relapse. A model to predict treatment intensification was developed using practical predictors, although its performance was modest.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41927-022-00274-y.

Is the Rheumatoid Arthritis Impact of Disease (RAID) score a meaningful instrument for other inflammatory rheumatic diseases? A cross-sectional analysis of data from the German National Database

To analyse the performance of the rheumatoid arthritis impact of disease (RAID) score in patients with ankylosing spondylitis, polymyalgia rheumatica, systemic lupus erythematosus, primary Sjögren’s syndrome, idiopathic inflammatory myositis and systemic sclerosis, as compared with rheumatoid arthritis (RA).

Methods

A total of 12 398 patients from the German National Database were included. For each diagnosis, we calculated age-adjusted/sex-adjusted partial correlation coefficients between RAID and patient global (PtGl) health, PtGl disease activity, physician global (PhGl) disease activity, Well-Being Index (WHO-5) and EuroQoL-5 Dimensions (EQ-5D). As a measure of agreement, the mean differences between the RAID and other outcomes were compared with the respective differences for RA. The effect of each diagnosis on the difference between RAID and the other scores was assessed with linear regression, with RA as the reference.

Results

Across all diagnoses, RAID correlated strongly with PtGl health (0.71–0.83), moderately to strongly with PtGl disease activity (0.59–0.79), WHO-5 (0.65–0.81) and EQ-5D (0.68–0.73) and weakly with PhGl disease activity (0.23–0.38). Mean differences were calculated for RAID and PtGl disease activity (0 to −0.6), PtGl health (−0.4 to −0.9), WHO-5 (−0.7 to −1.3), EQ-5D (1.1 to 1.7) and PhGl disease activity (1.4 to 2.2). Discrepancies between other scores and RAID were comparable to RA. Linear regression revealed no clinically relevant effect of any of the diagnoses on the difference between RAID and the other outcomes.

Conclusion

The RAID score performs comparably across all diagnoses investigated. This supports the use of RAID for measuring the impact also of other rheumatic diseases.

Measurement properties of the PolyMyalgia Rheumatica Activity Score (PMR-AS): a systematic literature review

Objective

To perform a COnsensus-based Standards for the selection of health Measurement Instruments (COSMIN) based Systematic Literature Review of measurement properties of the Polymyalgia Rheumatica Activity Score (PMR-AS).

Methods

Pubmed, EMBASE, and CINAHL were broadly searched. English full text articles, with (quantitative) data on at least 5 PMR patients using the PMR-AS were selected. Seven hypotheses for construct validity and three for responsiveness, concerning associations with erythrocyte sedimentation rate, physical function, quality of life, clinical disease states, ultrasound, and treatment response, were formulated. Articles usable to assess - COSMIN based - structural validity, internal consistency, reliability, measurement error, or hypotheses on construct validity or responsiveness were selected and assessed based on COSMIN criteria.

Results

From the 26 articles using the PMR-AS we were able to use 12 articles. Structural validity, internal consistency, construct validity, and responsiveness were assessed in one, two, eight, and three articles respectively. Insufficient evidence was found to confirm structural validity and internal consistency. No data was found on reliability or measurement error. Although 60% and 67% of hypotheses tested for construct validity and responsiveness were confirmed respectively, there was insufficient evidence to meet criteria for good measurement properties.

Conclusion

Whilst there is some promising evidence for construct validity and responsiveness of the PMR-AS, it is lacking for other properties and overall falls short of criteria for good measurement properties. Therefore, further research is needed to assess its role in clinical research and care.

Polymyalgia rheumatica: A case series from Colombia and analysis of Latin America

OBJECTIVE

Polymyalgia rheumatica (PMR) is the most common inflammatory disease in patients over 50 years. Information about the disease in Latin America (LATAM) is scarce. We aimed to evaluate a group of Colombian patients with PMR and to conduct a systematic review of PMR in LATAM.

METHODS

A multicentric retrospective study was performed. Medical records of 256 PMR patients were evaluated. Patients were divided into two groups, those fulfilling the 2012 European League Against Rheumatism/American College of Rheumatology (EULAR/ACR) classification criteria for PMR and those who did not (i.e., clinical diagnosis). A systematic literature review and meta regression was performed comparing Colombian vs LATAM patients.

RESULTS

From 256 patients, 145 (56.6%) fulfilled the 2012 EULAR/ACR criteria, and 111 (43.3%) were classified by clinical diagnosis. Inflammatory bilateral shoulder pain, pelvic girdle aching, morning stiffness >45 min, elevated erythrocyte sedimentation rate (ESR), and C-reactive protein (CPR), and Methotrexate (MTX) prescription were more common in the 2012 EULAR/ACR group. None of the included patients presented overt polyautoimmunity (PolyA), whereas up to 24% exhibited latent PolyA. In addition, these patients showed high frequency of malignancy (7.59%). In the meta regression analysis, Colombian patients exhibited lower ESR levels, and were less likely to develop giant cell arteritis (GCA) as compared to the rest of LATAM data.

CONCLUSION

Patients with PMR in LATAM exhibit similar phenotypes from other cohorts worldwide. Malignancy, GCA and latent PolyA should be considered in the routine clinical follow-up of patients with PMR.