Over 20% of PsA Patients Report Widespread Pain, 10% Meet Fibromyalgia Criteria

Philip Mease, MD
Credit: National Psoriasis Foundation

More than 1 in 5 with psoriatic arthritis (PsA) report experiencing widespread pain, with 1 in 10 fulfilling criteria for fibromyalgia, according to a recent analysis of patients with PsA.

An analysis of data from more than 1800 patients within the CorEvitas PsA registry, results of the study also provide insight into factors and patient characteristics associated with increased likelihood of expiring widespread pain or fibromyalgia among those with PsA.¹

“This study is the first in the US to characterize FM in a large real world psoriatic arthritis cohort utilizing the Widespread Pain Index/Symptom Severity Scale (WPI/SSS) measure of [fibromyalgia] as defined in the 2016 [fibromyalgia] diagnostic criteria, a validated pragmatic measure which can be applied in both research populations as well as clinical practice,” wrote investigators.¹

A disease characterized by symptoms that often mirror those of other conditions, diagnosis of fibromyalgia represents a persistent challenge in clinical settings, with many suggesting the disease is underrecognized while other research purports potential overdiagnosis of the condition. Citing deficiencies and limitations in previous research on the relationship between fibromyalgia, pain, and PsA, a team of investigators, which was led by Philip Mease, MD, of the Providence Swedish Health and University of Washington School of Medicine, launched the current study to better illustrate the importance of assessment and identification of fibromyalgia and widespread pain with the aim of improving individual management.^1,2

With this in mind, investigators designed a of patients within the CorEvitas PsA registry. a prospective, multicenter, observational, disease-based registry, the CorEvitas PsA registry was launched in 2013 and collects longitudinal, real-world data from adult patients receiving care from a cohort of 302 participating provides across 30 states. Investigators described 3 specific objectives for their study: to estimate the prevalence of fibromyalgia and widespread pain among patients with PsA, determine factors associated with incidence of fibromyalgia and widespread pain, and better understand associations between presence and disease severity in PsA.¹

For the purpose of analysis, prevalence was assessed by the Widespread Pain Index (WPI) and Symptom Severity Scale (SSS) whereas effect of concomitant fibromyalgia and widespread on disease was evaluated using the Clinical Disease Activity in Psoriatic Arthritis (cDAPSA) score. A total, of 1823 PsA patients from the registry met inclusion criteria for the study, which required patients to be 18 years or older, have a diagnosis of PsA, and have an in-person visit after May 2020.¹

Among this cohort, 11.1% fulfilled the fibromyalgia definition and 20.6% fulfilled the widespread pain definition. Compared to those without fibromyalgia, those with fibromyalgia were more likely to be female (51.5% vs 73.3%), have shorter disease duration (9.69 [SD, 9.06] vs 7.53 [SD, 7.70] years; P = .0001), increased HAQ (0.61 [SD, 0.62] vs 1.39 [SD, 0.60]; P <.001), increased BMI (SD, 31.87 [SD, 7.53] vs 33.82 [SD, 8.29] kg/m2; P = .001), and increased Charlson comorbidity index (1.33 [SD, 0.59] vs 1/49 [SD, 0.75]; P <.001).¹

Further analysis revealed these patients were also more likely to have a history of CVD(11.8% vs 18.8%; P = .004), history of physician-reported fibromyalgia (0.7% vs 5.0%), less alcohol use (60.5% vs 47.5%; P = .001), not be fully employed (49.5% vs 35.1%; P <.001), report use of narcotics/opioids (5.0% vs 12.9%; P <.001), and have greater rates of patient-reported depression (5.2% vs 14.4%; P <.001) and anxiety (6.2% vs 17.8%; P <.001).¹

When compared to those without fibromyalgia and widespread pain, assessments of disease activity revealed mean differences in cDAPSA of 13.02 (95% Confidence Interval [CI], 10.42 to 15.63) for those with fibromyalgia and 11.94 (95% CI, 9.96 to 13.92) for those with widespread pain. Investigators also pointed out swollen joint count was also greater among those with fibromyalgia and widespread pain (1.30; 95% CI, 0.01 to 1.87).¹

Investigators noted multiple limitations within their study, including those inherent with the cross-sectional nature of the study, lack of data on physical activity, physical therapy, or other nonpharmacologic interventions, and lack of data verifying the representativeness of the CorEvitas registry as it relates to patients with PsA.

“As clinicians, we strive to guide therapy to achieve a target of remission or low disease activity and need to be aware of contextual factors which may make accurate assessment of inflammatory disease activity less reliable,” investigators wrote.¹

References:

1. _{^{Mease P, Reed G, Ogdie A, Pappas DA, Kremer JM. Prevalence of Fibromyalgia and Widespread Pain in Psoriatic Arthritis: Association with Disease Severity Assessment in a Large US Registry. Arthritis Care Res (Hoboken). Published online May 12, 2024. doi:10.1002/acr.25358}}
2. _{^{Häuser W, Sarzi-Puttini P, Fitzcharles MA. Fibromyalgia syndrome: under-, over- and misdiagnosis. Clin Exp Rheumatol. 2019;37 Suppl 116(1):90-97.}}