AxSpA patients who also meet criteria for fibromyalgia: identifying distinct patient clusters using data from a UK national register (BSRBR-AS)

Abstract

Background Around 1 in 8 patients with axial spondyloarthritis (axSpA) also meet criteria for fibromyalgia and such patients have considerable unmet need. Identifying effective therapy is important but to what extent fibromyalgia-like symptoms relate to axSpA disease severity has not been established. The aim of the current analysis was to determine whether distinct clusters of axSpA patients exist and if so to determine a) whether they differ in terms of prevalence of fibromyalgia and b) the features of patients in clusters with high prevalence. Methods The British Society for Rheumatology Biologics Register (BSRBR-AS) recruited axSpA patients from 83 centres 2012–2017. Clinical data, and information from patients was collected (including research criteria for fibromyalgia). Cluster analysis was undertaken using split samples for development and validation both in the whole population and the sub-group which met fibromyalgia criteria. Results One thousand three hundred thirty-eight participants were included of whom 23% met research criteria for fibromyalgia. Four clusters were identified. Two exhibited very high disease activity, one which was primarily axial ( n = 347) and a smaller cluster ( n = 32) with axial and peripheral disease, and in both groups more than half of members met criteria for fibromyalgia. The remaining two clusters ( n = 437, n = 462) had overall less severe disease however the one which showed greater disease activity and poorer quality of life had a higher proportion meeting fibromyalgia criteria (16% v. 4%). Within those meeting fibromyalgia criteria there were three clusters. The two main groups were defined by level of symptom severity with a smaller third cluster noted to have high average swollen and tender joint counts and high levels of comorbidity. Conclusions The major feature defining clusters with a high proportion of persons meeting criteria for fibromyalgia is high axSpA disease activity although clusters with features of fibromyalgia in the absence of high disease activity also show moderately high prevalence. Management may be most successful with pharmacologic therapy to target inflammation but enhanced by the concurrent use of non-pharmacologic therapy in such patients.

Employment, Work Productivity, and Biologic Treatments in Self-Reported Axial Spondyloarthritis: a Cross-Sectional Study in a Female Predominant Population from the ArthritisPower Registry

“…This is not surprising, as results from previous studies have shown that axSpA patients with concomitant fibromyalgia have more disease activity, functional impairment, fatigue, pain, and poorer quality of life than patients without fibromyalgia [ 37 , 38 ]. Studies have also found that high axSpA disease activity and widespread pain are associated with the development of fibromyalgia [ 39 – 41 ].…”

The changing states of fibromyalgia in patients with axial spondyloarthritis: results from the British Society of Rheumatology Biologics Register for Ankylosing Spondylitis

“…Starting on a TNFi is associated with recovering from FM. The coexistence of FM in patients with axSpA has previously been found to be associated with high levels of axSpA disease activity in cross-sectional studies [ 16 , 17 ]. The current study adds to this body of knowledge by providing evidence that while high levels of axSpA disease activity are associated with future FM development, low levels of axSpA disease activity are associated with recovery from FM.…”

Comparing the Impact of Symptoms and Health Care Experiences of People Who Have and Have Not Received a Diagnosis of Fibromyalgia: A Cross‐Sectional Survey Within the PACFiND Study

“…Prevalence is even higher in people with inflammatory musculoskeletal conditions; for example, patients with rheumatoid arthritis, psoriatic arthritis, and ankylosing spondylitis have been shown in a meta-analysis to have prevalence proportions of 21%, 18%, and 13%, respectively (4). The diagnosis of fibromyalgia can be particularly challenging when the clinical features (such as pain, fatigue, and tenderness on palpation) are shared with the coexisting condition (5).…”

“…Prevalence is even higher in people with inflammatory musculoskeletal conditions; for example, patients with rheumatoid arthritis, psoriatic arthritis, and ankylosing spondylitis have been shown in a meta‐analysis to have prevalence proportions of 21%, 18%, and 13%, respectively (4). The diagnosis of fibromyalgia can be particularly challenging when the clinical features (such as pain, fatigue, and tenderness on palpation) are shared with the coexisting condition (5).

People whose symptoms meet the criteria for fibromyalgia have symptoms whose impact is very similar to those who have received a fibromyalgia diagnosis. The impact of symptoms in people who meet the criteria for fibromyalgia (or who have received a diagnosis) is much greater than in people with chronic pain. The diagnosis of fibromyalgia may be overlooked in men. Particular attention needs to be paid for improving work outcomes in those with fibromyalgia symptoms/diagnosis.

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