Prevalence of Pain and Factors Associated with Pain in Patients with Idiopathic Inflammatory Myopathies.

Abstract

Objective: Pain is an often overlooked and understudied symptom in inflammatory myopathies (IIM). In this study, our goal is to examine the prevalence of pain and factors associated with pain in adults with IIM.

Methods: FORWARD is a US-based prospective registry of adults with rheumatic diseases recruited from rheumatology clinics. Participants had physician diagnosis of IIM and completed questionnaires on pain, fatigue, physical function, disease activity, and sociodemographic variables. Pain prevalence was examined in demographic and disease subgroups. Regression models were performed to identify any factors associated with higher levels of pain (>3 pain on visual analog scale). The relationship between pain and outcome variables was examined through Pearson correlations, t-test and chi-square test.

Results: A total of 189 IIM patients (age 55 years ± 14, 78% women) from FORWARD Databank were included in the study. Approximately 86% reported pain with an average of 3.5 on a 10-point visual analog scale. One in four patients were on opioids. Approximately 62-63% reported joint and muscle pain, respectively. Pain prevalence was similar across subgroups of disease subtype, sex, race, smoking, and obesity. Patient global disease activity was significantly associated with higher pain levels in multivariable models. Pain was significantly associated with worse physical function, fatigue, quality of life and health satisfaction.

Conclusion: Pain is prevalent and associated with poor outcomes in patients with IIM. Pain is closely linked with patient global disease activity. Results highlight the critical need to better understand the pain experienced by these patients to best address their needs.