"An impediment to living life": why and how should we measure stiffness in polymyalgia rheumatica?

The spectrum of giant cell arteritis through a rheumatology lens

Treatment of giant cell arteritis (GCA) aims initially to prevent acute visual loss, and subsequently to optimise long-term quality of life. Initial prevention of acute visual loss in GCA is well-standardised with high-dose glucocorticoid therapy but in the longer term optimising quality of life requires tailoring of treatment to the individual. The licensing of the IL-6 receptor inhibitor tocilizumab combined with advances in vascular imaging have resulted in many changes to diagnostic and therapeutic practice. Firstly, GCA is a systemic disease that may involve multiple vascular territories and present in diverse ways. Broadening of the "spectrum" of what is called GCA has been crystallised in the 2022 GCA classification criteria. Secondly, the vascular inflammation of GCA frequently co-exists with the extracapsular musculoskeletal inflammation of the related disease, polymyalgia rheumatica (PMR). Thirdly, GCA care must often be delivered across multiple specialities and healthcare organisations requiring effective interprofessional communication. Fourthly, both GCA and PMR may follow a chronic or multiphasic disease course; long-term management must be tailored to the individual patient's needs. In this article we focus on some areas of current rheumatology practice that ophthalmologists need to be aware of, including comprehensive assessment of extra-ocular symptoms, physical signs and laboratory markers; advanced imaging techniques; and implications for multi-speciality collaboration.

Polymyalgia rheumatica shows metabolomic alterations that are further altered by glucocorticoid treatment: Identification of metabolic correlates of fatigue

OBJECTIVE

In polymyalgia rheumatica (PMR), glucocorticoids (GCs) relieve pain and stiffness, but fatigue may persist. We aimed to explore the effect of disease, GCs and PMR symptoms in the metabolite signatures of peripheral blood from patients with PMR or the related disease, giant cell arteritis (GCA).

METHODS

Nuclear magnetic resonance spectroscopy was performed on serum from 40 patients with untreated PMR, 84 with new-onset confirmed GCA, and 53 with suspected GCA who later were clinically confirmed non-GCA, and 39 age-matched controls. Further samples from PMR patients were taken one and six months into glucocorticoid therapy to explore relationship of metabolites to persistent fatigue. 100 metabolites were identified using Chenomx and statistical analysis performed in SIMCA-P to examine the relationship between metabolic profiles and, disease, GC treatment or symptoms.

RESULTS

The metabolite signature of patients with PMR and GCA differed from that of age-matched non-inflammatory controls (R2 > 0.7). There was a smaller separation between patients with clinically confirmed GCA and those with suspected GCA who later were clinically confirmed non-GCA (R2 = 0.135). In PMR, metabolite signatures were further altered with glucocorticoid treatment (R2 = 0.42) but did not return to that seen in controls. Metabolites correlated with CRP, pain, stiffness, and fatigue (R2 ≥ 0.39). CRP, pain, and stiffness declined with treatment and were associated with 3-hydroxybutyrate and acetoacetate, but fatigue did not. Metabolites differentiated patients with high and low fatigue both before and after treatment (R2 > 0.9). Low serum glutamine was predictive of high fatigue at both time points (0.79-fold change).

CONCLUSION

PMR and GCA alter the metabolite signature. In PMR, this is further altered by glucocorticoid therapy. Treatment-induced metabolite changes were linked to measures of inflammation (CRP, pain and stiffness), but not to fatigue. Furthermore, metabolite signatures distinguished patients with high or low fatigue.

Treatment of polymyalgia rheumatica: British Society for Rheumatology guideline scope

The last British Society for Rheumatology (BSR) guideline on PMR was published in 2009. The guideline needs to be updated to provide a summary of the current evidence for pharmacological and non-pharmacological management of adults with PMR. This guideline is aimed at healthcare professionals in the UK who directly care for people with PMR, including general practitioners, rheumatologists, nurses, physiotherapists, occupational therapists, pharmacists, psychologists and other health professionals. It will also be relevant to people living with PMR and organisations that support them in the public and third sector, including charities and informal patient support groups. This guideline will be developed using the methods and processes outlined in the BSR Guidelines Protocol. Here we provide a brief summary of the scope of the guideline update in development.

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.

Sarilumab for Relapse of Polymyalgia Rheumatica during Glucocorticoid Taper

BACKGROUND

More than half of patients with polymyalgia rheumatica have a relapse during tapering of glucocorticoid therapy. Previous studies have suggested that interleukin-6 blockade may be clinically useful in the treatment of polymyalgia rheumatica. Sarilumab, a human monoclonal antibody, binds interleukin-6 receptor α and efficiently blocks the interleukin-6 pathway.

METHODS

In this phase 3 trial, we randomly assigned patients in a 1:1 ratio to receive 52 weeks of a twice-monthly subcutaneous injection of either sarilumab (at a dose of 200 mg) plus a 14-week prednisone taper or placebo plus a 52-week prednisone taper. The primary outcome at 52 weeks was sustained remission, which was defined as the resolution of signs and symptoms of polymyalgia rheumatica by week 12 and sustained normalization of the C-reactive protein level, absence of disease flare, and adherence to the prednisone taper from weeks 12 through 52.

RESULTS

A total of 118 patients underwent randomization (60 to receive sarilumab and 58 to receive placebo). At week 52, sustained remission occurred in 28% (17 of 60 patients) in the sarilumab group and in 10% (6 of 58 patients) in the placebo group (difference, 18 percentage points; 95% confidence interval, 4 to 32; P = 0.02). The median cumulative glucocorticoid dose at 52 weeks was significantly lower in the sarilumab group than in the placebo group (777 mg vs. 2044 mg; P<0.001). The most common adverse events with sarilumab as compared with placebo were neutropenia (15% vs. 0%), arthralgia (15% vs. 5%), and diarrhea (12% vs. 2%). More treatment-related discontinuations were observed in the sarilumab group than in the placebo group (12% vs. 7%).

CONCLUSIONS

Sarilumab showed significant efficacy in achieving sustained remission and reducing the cumulative glucocorticoid dose in patients with a relapse of polymyalgia rheumatica during glucocorticoid tapering. (Funded by Sanofi and Regeneron Pharmaceuticals; SAPHYR ClinicalTrials.gov number, NCT03600818.).

Clinical presentation and treatment response in patients with polymyalgia rheumatica and giant cell arteritis during a 40-week follow-up

Objectives

The aim was to study the clinical features of PMR/GCA and clinical predictors of treatment response during a 40-week follow-up period.

Methods

Clinical data on 77 patients with newly diagnosed PMR/GCA who were treated with oral glucocorticoids were gathered at baseline and during a 40-week follow-up period. A unilateral temporal artery biopsy (TAB) and ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) PET/CT were undertaken at diagnosis. In total, each patient was seen on five occasions (i.e. baseline and weeks 4, 16, 28 and 40). Treatment response was assessed by considering clinical evaluations and results of inflammatory markers.

Results

Of 77 patients [49 (63.6%) female; mean age 71.8 (8.0) years], 64 (83.1%) patients had pure PMR, 10 (13.0%) concomitant PMR and GCA, and 3 (3.9%) pure GCA. The patients reported that clinical symptoms, apart from scalp pain and duration of morning stiffness, improved significantly at week 4 and remained lower at week 40 compared with the relative frequencies at baseline. Besides, all components of physical examination showed significant improvement and remained lower at week 40 compared with the baseline. A complete response was seen in 68.7, 62.9, 44.1 and 33.3% of patients at weeks 4, 16, 28 and 40, respectively. Several clinical features, including female biological sex, younger age, fewer relapses and a lower level of baseline ESR, were significantly associated with a better treatment response. Treatment response during the follow-up period was independent of TAB results and fluorodeoxyglucose uptakes on ¹⁸F-FDG PET/CT at diagnosis.

Conclusion

Obtaining valid disease-specific outcome measures for evaluating treatment efficacy in PMR and GCA that can be applied universally is clearly an unmet clinical need.

Trial registration

ClinicalTrials.gov, https://clinicaltrials.gov, NCT02985424.

Feasibility and usefulness of a fast-track clinic for patients suspected of polymyalgia rheumatica: notes for a work schedule through a narrative review of published literature

Objectives

Fast-track clinics (FTC) have been introduced in different fields and have been reporting significant outcomes in terms of reducing mortality, morbidity, and financial costs. To date, scarce evidence is available for FTC specific for patients suspected of polymyalgia rheumatica (PMR). The primary aim of our paper is to provide an overview of the clinical impact of PMR on patients and the healthcare system by analysing multiple aspects: the median time from onset of symptoms to diagnosis and the burden of the disease both on the healthcare system costs and on patients' quality of life (QoL). Secondarily, based on these data, we aim to discuss the potential advantages and feasibility of a PMR FTC in everyday clinical practice.

Material and methods

We performed a narrative non-systematic review (PRISMA protocol not followed) of PubMed and Medline (OVID interface) with the following MeSH terms: [polymyalgia rheumatica AND diagnosis OR diagnosis, delayed OR patient care OR early diagnosis OR length of stay OR costs OR healthcare system OR quality of life] or [polymyalgia rheumatica AND glucocorticoids AND side effects]. We decided to exclude every paper that did not report raw data in terms of diagnostic time or delay, hospitalization rate, socio-economic costs on the healthcare system, patients' QoL, and glucocorticoids-related events in PMR patients. Papers focused primarily on giant cell arteritis patients with overlapping PMR were also excluded. Abstract archives of the European League Against Rheumatism (EULAR) and the American College of Rheumatology (ACR) congresses of the last 10 years were screened and included in the search if raw data were available. Each paper's reference list was scanned for additional publications meeting this study's aims. When papers reported data partially presented in previous articles, we opted to use the most recently published data.

Results

According to our literature review, a PMR FTC might lighten the burden of the disease. Nevertheless, its feasibility depends mostly on the resources of the national health system and of the territorial health district, which are heterogeneously limited. The usefulness of PMR FTCs depends on closer collaboration with the general practitioner because he/she is the first clinician to visit patients with PMR.

Conclusions

Polymyalgia rheumatica fast-track clinics might lighten the burden of the disease. However, it has some limits that should carefully assessed in planning health policies.

Not just pain and morning stiffness duration in the daily experience of patients with polymyalgia rheumatica. Does the rheumatologist listen to all patient-reported outcomes?

Patient-reported outcomes (PROs) provide a means for patients to communicate with their care teams about their disease. Polymyalgia rheumatica (PMR) is considered to be one of the most common inflammatory rheumatic diseases in older adults. The Visual Analogue Scale (VAS) of pain is the only PRO assessed by the PMR activity score (PMR-AS), which is still the only validated score for monitoring disease activity in patients affected with PMR. Other PROs such as fatigue, sleep disturbances, depressive symptoms, and patient’s perspective related to adverse effects of prednisolone are still unmet needs. This short communication suggests the gerontorheumatological outpatient clinic as an answer.

Posterior to anterior spinal stiffness measured in a sample of 127 secondary care low back pain patients

BACKGROUND

The sensation of spinal stiffness is a commonly reported symptom among back pain patients, with the clinical assessment of spinal stiffness usually being part of the decision-making process when deciding on providing manual treatment of low back pain. While any relationship between spinal stiffness and low back pain is likely to be multifactorial, prior exploration of this relationship has been overly simplistic (e.g., univariate regression analyses). The purpose of this study was to address this gap by taking a broader approach to compare instrumented measures of spinal stiffness to demographic characteristics, pain phenotypes, psychometrics, and spine-related disability in a sample of secondary care low back pain patients using multivariate regression analysis.

METHODS

Instrumented spinal stiffness measures from 127 patients in secondary care were used to calculate terminal and global spinal stiffness scores. A best subset analysis was used to find the subsets of 14 independent variables that most accurately predicted stiffness based on the evaluation of the adjusted R-square, Akaike Information Criteria, and the Bayesian Information Criteria.

FINDINGS

In the resulting multivariate models, sex (p < 0.001) and age (p < 0.001) were the primary determinants of terminal stiffness, while global stiffness was primarily determined by age (p = 0.003) and disability (p = 0.024).

INTERPRETATION

Instrumented measures of spinal stiffness are multifactorial in nature, and future research into this area should make use of multivariate analyses.

Feasibility and Face Validity of Outcome Measures for Use in Future Studies of Polymyalgia Rheumatica: An OMERACT Study

OBJECTIVE

To survey participants with polymyalgia rheumatica (PMR) to evaluate the face validity, acceptability, and domain match of proposed candidate outcome measures.

METHODS

A structured, online, anonymous survey was disseminated by patient support groups through their networks and online forums. The candidate outcome measures comprised (1) visual analog scale (VAS) and numerical rating score (NRS) to assess pain; (2) VAS, NRS, and duration to assess stiffness; (3) the modified Health Assessment Questionnaire and Health Assessment Questionnaire Disability Index to assess physical function; and (4) C-reactive protein and erythrocyte sedimentation rate to assess inflammation. Free-text answers were analyzed using descriptive thematic analysis to determine respondents' views of the candidate instruments.

RESULTS

Seventy-eight people with PMR from 6 countries (UK, France, USA, Canada, Australia, and New Zealand) participated in the survey. Most respondents agreed candidate instruments were acceptable or "good to go." Free-text analysis identified 5 themes that participants considered inadequately covered by the proposed instruments. These related to (1) the variability, context, and location of pain; (2) the variability of stiffness; (3) fatigue; (4) disability; and (5) the correlation of inflammatory marker levels and severity of symptoms, sometimes reflecting disease activity and other times not.

CONCLUSION

Participants reported additional aspects of their experience that are not covered by the proposed instruments, particularly for the experience of stiffness and effect of fatigue. New patient-reported outcome measures are required to increase the relevance of results from clinical trials to patients with PMR.

Longitudinal clusters of pain and stiffness in polymyalgia rheumatica: 2-year results from the PMR Cohort Study

Objectives

To investigate potential subgroups of primary care–diagnosed patients with PMR based on self-reported pain and stiffness severity over time.

Methods

A total of 652 people with an incident PMR diagnosis were recruited from English general practices and completed a baseline postal questionnaire. They were followed up with a further six questionnaires over a 2 year period. A total of 446 people completed the 2 year follow-up. Pain and stiffness were reported on a 0–10 numerical rating scale. Latent class growth analysis was used to estimate the joint trajectories of pain and stiffness over time. A combination of statistical and clinical considerations was used to choose the number of clusters. Characteristics of the classes were described.

Results

Five clusters were identified. One cluster represented the profile of ‘classical’ PMR symptoms and one represented sustained symptoms that may not be PMR. The other three clusters displayed a partial recovery, a recovery followed by worsening and a slow, but sustained recovery. Those displaying classical PMR symptoms were in better overall health at diagnosis than the other groups.

Conclusion

PMR is a heterogeneous condition, with a number of phenotypes. The spectrum of presentation, as well as varying responses to treatment, may be related to underlying health status at diagnosis. Future research should seek to stratify patients at diagnosis to identify those likely to have a poor recovery and in need of an alternative treatment pathway. Clinicians should be aware of the different experiences of patients and monitor symptoms closely, even where there is initial improvement.

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

OBJECTIVE

To systematically identify the outcome measures and instruments used in clinical studies of polymyalgia rheumatica (PMR) and to evaluate evidence about their measurement properties.

METHODS

Searches based on the MeSH term "polymyalgia rheumatica" were carried out in 5 databases. Two researchers were involved in screening, data extraction, and risk of bias assessment. Once outcomes and instruments used were identified and categorized, key instruments were selected for further review through a consensus process. Studies on measurement properties of these instruments were appraised against the COSMIN-OMERACT (COnsensus-based Standards for the selection of health Measurement Instruments-Outcome Measures in Rheumatology) checklist to determine the extent of evidence supporting their use in PMR.

RESULTS

Forty-six studies were included. In decreasing order of frequency, the most common outcomes (and instruments) used were markers of systemic inflammation [erythrocyte sedimentation rate (ESR), C-reactive protein (CRP)], pain [visual analog scale (VAS)], stiffness (duration in minutes), and physical function (elevation of upper limbs). Instruments selected for further evaluation were ESR, CRP, pain VAS, morning stiffness duration, and the Health Assessment Questionnaire. Five studies evaluated measurement properties of these instruments, but none met all of the COSMIN-OMERACT checklist criteria.

CONCLUSION

Measurement of outcomes in studies of PMR lacks consistency. The critical patient-centered domain of physical function is poorly assessed. None of the candidate instruments considered for inclusion in the core outcome set had high-quality evidence, derived from populations with PMR, on their full range of measurement properties. Further studies are needed to determine whether these instruments are suitable for inclusion in a core outcome measurement set for PMR.

Treat to Target: A Valid Concept for Management of Polymyalgia Rheumatica and Giant Cell Arteritis?

Giant cell arteritis (GCA) and polymyalgia rheumatica (PMR) are common inflammatory diseases of the elderly. They have variable clinical courses and are usually treated with glucocorticoids (GCs). Relapses are frequent in both conditions. Physicians should balance the tradeoff of treatment-related adverse events and risk of relapse. The ultimate goal of treatment is control of the disease while maintaining patient well-being. A treat-to-target approach may achieve the aim of controlling inflammation and preserving patient's functioning and quality of life, and would require pursuit and evaluation of clinical, laboratory, imaging, and structural targets to tackle the different manifestations of GCA and PMR.

The association of pain and stiffness with fatigue in incident polymyalgia rheumatica: baseline results from the polymyalgia rheumatica cohort study

We aimed to examine the association between pain, stiffness and fatigue in newly diagnosed polymyalgia rheumatica (PMR) patients using baseline data from a prospective cohort study. Fatigue is a known, but often ignored symptom of PMR. Newly diagnosed PMR patients were recruited from general practice and mailed a baseline questionnaire. This included a numerical rating scale for pain and stiffness severity, manikins identifying locations of pain and stiffness and the FACIT-Fatigue questionnaire. A total of 652 PMR patients responded (88.5%). The mean age of responders was 72.6 years (SD 9.0) and the majority were female (62.0%). Manikin data demonstrated that bilateral shoulder and hip pain and stiffness were common. The mean fatigue score (FACIT) was 33.9 (SD 12.4). Adjusted regression analysis demonstrated that a higher number of pain sites (23-44 sites) and higher pain and stiffness severity were associated with greater levels of fatigue. In newly diagnosed PMR patients, fatigue was associated with PMR symptom severity.

Diagnosis of polymyalgia rheumatica usually means a favourable outcome for your patient

Polymyalgia rheumatica (PMR) is a unique disease of elderly people, traditionally diagnosed based on a clinical picture. A typical case is a combination of severe musculoskeletal symptoms and systemic inflammatory response with spectacular response to corticosteroids treatment. The severity of symptoms may be surprising in older patients where immunosenescence is normally expected. However, PMR may be diagnosed in haste if there is a temptation to use this diagnosis as a shortcut to achieve rapid therapeutic success. Overdiagnosis of PMR may cause more problems compared to underdiagnosis. The 2012 PMR criteria proposed by European League against Rheumatism/American College of Rheumatology aim to minimize the role of clinical intuition and build on more objective features. However, questions arise if this is possible in PMR. This has been discussed in this review.

Feeling stiffness in the back: a protective perceptual inference in chronic back pain

Does feeling back stiffness actually reflect having a stiff back? This research interrogates the long-held question of what informs our subjective experiences of bodily state. We propose a new hypothesis: feelings of back stiffness are a protective perceptual construct, rather than reflecting biomechanical properties of the back. This has far-reaching implications for treatment of pain/stiffness but also for our understanding of bodily feelings. Over three experiments, we challenge the prevailing view by showing that feeling stiff does not relate to objective spinal measures of stiffness and objective back stiffness does not differ between those who report feeling stiff and those who do not. Rather, those who report feeling stiff exhibit self-protective responses: they significantly overestimate force applied to their spine, yet are better at detecting changes in this force than those who do not report feeling stiff. This perceptual error can be manipulated: providing auditory input in synchrony to forces applied to the spine modulates prediction accuracy in both groups, without altering actual stiffness, demonstrating that feeling stiff is a multisensory perceptual inference consistent with protection. Together, this presents a compelling argument against the prevailing view that feeling stiff is an isomorphic marker of the biomechanical characteristics of the back.

The OMERACT Core Domain Set for Outcome Measures for Clinical Trials in Polymyalgia Rheumatica

OBJECTIVE

To inform development of a core domain set for outcome measures for clinical trials in polymyalgia rheumatica (PMR), we conducted patient consultations, a systematic review, a Delphi study, and 2 qualitative studies.

METHODS

Domains identified by 70% or more of physicians and/or patients in the Delphi study were selected. The conceptual framework derived from the 2 qualitative research studies helped inform the meaning of each domain and its relationship to the others. The draft core domain set was refined by further discussion with patients and physicians who had participated in the Delphi study. At the Outcome Measures in Rheumatology (OMERACT) 2016, the domains were discussed and prioritized by 8 breakout groups. Formal voting took place at the end of the workshop and in the final plenary.

RESULTS

Ninety-three percent of voters in the final plenary agreed that the inner core of domains considered mandatory for clinical trials of PMR should consist the following: laboratory markers of systemic inflammation, pain, stiffness, and physical function. Patient's global and fatigue were considered important but not mandatory (outer core). The research agenda included psychological impact, weakness, physical activity, participation, sleep, imaging, and health-related quality of life.

CONCLUSION

This core domain set was considered sufficiently well-defined that the next step will be to apply the OMERACT Filter 2.0 Instrument Selection Algorithm to select candidate instruments for a subsequent "deeper dive" into the data. This will allow instruments to be mapped onto each of our core domains to derive a core outcome set for PMR.

Association between characteristics of pain and stiffness and the functional status of patients with incident polymyalgia rheumatica from primary care

This paper aims to examine the relationship between different characteristics of pain and stiffness and the functional status of patients with newly diagnosed polymyalgia rheumatica (PMR). Baseline analysis of an inception cohort study was conducted. Patients aged ≥18 years, with a new diagnosis of PMR were recruited from 382 English general practices. Participants were mailed a baseline questionnaire, including separate pain and stiffness manikins and numerical rating scales (NRS), a question on their ability to raise their arms above their head and the modified Health Assessment Questionnaire (mHAQ) to examine participants’ functional status. Linear regression analysis, reported as regression co-efficients (95% confidence intervals (95% CI)), was used to assess the association of pain and stiffness with function, initially unadjusted and then adjusted for age, gender, deprivation status, smoking status, BMI, anxiety and depression. Six hundred fifty two patients responded to the baseline survey (88.5%). The majority (88.2%) reported no, or mild impairment in their functional status. Adjusted linear regression analysis demonstrated that high (NRS ≥8) pain (0.20 (95% CI 0.10–0.28)) or stiffness (0.18 (0.09–0.26)) ratings, an increasing number of sites of pain (0.18 (0.06–0.29)) or stiffness (0.19 (0.08–0.31)) and shoulder pain (0.18 (0.05–0.31)), stiffness (0.10 (0.01–0.20)) and difficulty raising arms above one’s head (0.19 (0.10–0.28)) were all associated with increased functional impairment. The majority of newly diagnosed PMR patients reported no or minimal functional difficulty. However, those who experience severe or widespread pain or stiffness often have significant functional limitation in performing their daily activities and may be a subset worthy of additional focus in primary care.

Stiffness Is the Cardinal Symptom of Inflammatory Musculoskeletal Diseases, Yet Still Variably Measured: Report from the OMERACT 2016 Stiffness Special Interest Group

Objective.

The objectives of the Outcome Measures in Rheumatology (OMERACT) Stiffness special interest group (SIG) are to characterize stiffness as an outcome in rheumatic disease and to identify and validate a stiffness patient-reported outcome (PRO) in rheumatology.

Methods.

At OMERACT 2016, international groups presented and discussed results of several concurrent research projects on stiffness: a literature review of rheumatoid arthritis (RA) stiffness PRO measures, a qualitative investigation into the RA and polymyalgia rheumatica patient perspective of stiffness, data-driven stiffness conceptual model development, development and testing of an RA stiffness PRO measure, and a quantitative work testing stiffness items in patients with RA and psoriatic arthritis.

Results.

The literature review identified 52 individual stiffness PRO measures assessing morning or early morning stiffness severity/intensity or duration. Items were heterogeneous, had little or inconsistent psychometric property evidence, and did not appear to have been developed according to the PRO development guidelines. A poor match between current stiffness PRO and the conceptual model identifying the RA patient experience of stiffness was identified, highlighting a major flaw in PRO selection according to the OMERACT filter 2.0.

Conclusion.

Discussions within the Stiffness SIG highlighted the importance of further research on stiffness and defined a research agenda.

Characterising those with incident polymyalgia rheumatica in primary care: results from the PMR Cohort Study

Background

The aim was to characterise the sociodemographic, general health and polymyalgia rheumatica (PMR)-specific features of participants in a large inception cohort of patients with PMR diagnosed in UK primary care.

Methods

Patients (n = 739) with a new diagnosis of PMR were referred into the study and mailed a questionnaire detailing their general health and sociodemographic characteristics in addition to the symptoms of and treatment for PMR. Characteristics of responders and non-responders were compared and descriptive statistics were used to characterise the health of the cohort.

Results

A total of 654 individuals responded to the questionnaire (adjusted response 90.1 %). Responders and non-responders were similar in age, gender and deprivation (based on postcode). The mean (standard deviation) age of the recruited cohort was 72.4 (9.3) years; 62.2 % were female. The sample reported high levels of pain and stiffness (8 out of 10 on numerical rating scales) and reported stiffness that lasted throughout the day. High levels of functional impairment, fatigue, insomnia and polypharmacy were also reported. Overall, women reported worse general and PMR-specific health than did men.

Conclusions

This first primary care cohort of patients with incident PMR is similar in demographic terms to cohorts recruited in secondary care. However, the extent of symptoms, particularly reported stiffness, is higher than has been described previously. Given the majority of patients with PMR are exclusively managed in primary care, this cohort provides important information on the course of PMR in the community that will help clinicians managing this painful and disabling condition.

Whole-body MRI of patients with polymyalgia rheumatica identifies a distinct subset with complete patient-reported response to glucocorticoids

OBJECTIVES

To determine whether whole-body MRI defines clinically relevant subgroups within polymyalgia rheumatica (PMR) including glucocorticoid responsiveness.

METHODS

22 patients with PMR and 16 with rheumatoid arthritis (RA), untreated and diagnosed by consultant rheumatologists, underwent whole-body, multiple-joint MRI, scored by two experts. Patients with PMR reported whether they felt 'back to normal' on glucocorticoid therapy and were followed for a median of 2 years.

RESULTS

All patients with PMR were deemed to respond to glucocorticoids clinically. A characteristic pattern of symmetrical, extracapsular inflammation, adjacent to greater trochanter, acetabulum, ischial tuberosity and/or symphysis pubis, was observed in 14/22 of the PMR cases. In PMR, this pattern was associated with complete glucocorticoid response (p=0.01), higher pretreatment C-reactive protein (CRP) and serum interleukin-6 (IL-6), and better post-treatment fatigue and function. Only 1/14 in the extracapsular group could stop glucocorticoids within 1 year, compared with 4/7 of the others. A score derived from the five sites discriminating best between PMR and RA correlated with IL-6 (p<0.002). IL-6 levels ≥16.8 pg/mL had 86% sensitivity and 86% specificity for the extracapsular MRI pattern.

CONCLUSIONS

A subset of patients with rheumatologist-diagnosed PMR had a characteristic, extracapsular pattern of MRI inflammation, associated with elevated IL-6/CRP and with complete patient-reported glucocorticoid responsiveness.