HIGH FATIGUE SCORES in PATIENTS with IDIOPATHIC INFLAMMATORY MYOPATHIES: A MULTIGROUP COMPARATIVE STUDY from the COVAD E-SURVEY

ABSTRACT

Background: Idiopathic inflammatory myopathies (IIM) are a rare, multisystem, heterogeneous diseases, and contribute to high psychological burden. The patients' perception of physical health, deteriorating independence and social and environmental relationships may not always be a direct function of disease activity. To face with these aspects, several worldwide specialized organization have recommended the use of patient reported outcome measures (PROMs) both in clinical trials and observational studies to highlight patient's perception of the disease (1). Unfortunately, data on fatigue scores in IIM is limited. Objectives: We compared fatigue VAS scores in patients with IIM, autoimmune diseases (AIDs) and healthy controls (HCs) and triangulated them with PROMIS physical function in a large international cohort made up of answers from the e-survey regarding the COVID-19 Vaccination in Autoimmune Diseases (COVAD) study. Methods: Data of 16327 respondents was extracted from the COVAD database on August 31th 2021. VAS fatigue scores were compared between AID, HC and IIM using univariate followed by multivariate analysis after adjusting for baseline differences. We further performed a propensity score matched analysis on 1827 subjects after adjusting for age, gender and ethnicity. The Kruskal-Wallis test was used for continuous variables and chi-square test for categorical variables, and Bonferroni's correction was applied for the post hoc analyses considering IIMs as a reference group. Results: We analyzed answers from 6988 patients, with a mean age of 43.8 years (SD 16.2). The overall percentage of female was 72% and the population ethnicity was mainly composed of White (55.1%), followed by Asian (24.6%), and Hispanic (13.8%). The overall fatigue VAS was 3.6 mm (SD 2.7). IIMs VAS was 4.8 mm (SD 2.6), AIDs 4.5 mm (SD 2.6), and HC 2.8 mm (SD 2.6) (P <0,001). VAS fatigue scores of IIMs were comparable with AIDs (P 0.084), albeit signifcantly higher than the HCs (P <0,001). Notably, fatigue VAS was lower in IIMs than AIDs in two distinct subsets inactive disease as defned by the patient's perception and the 'excellent' general health condition group, where IIMs had worse scores (P <0,05). Interestingly, fatigue VAS was comparable in active disease defned by physician assessment, patient perception, based on general functional status, or when defned by steroid dose being prescribed. Notably, after propensity matched analysis of patients adjusting for gender, age and ethnicity (1.827 answers, I.e. 609 subjects per group, P =1) the differences disappeared and IIMs and AIDs had comparable fatigue levels across all levels of disease activity, although the fatigue discrepancies with HCs were substantially confrmed. After application of a multivariate linear regression analysis we found that lower fatigue VAS scores were related to HC (P <0,001), male gender (P <0,001), Asian and Hispanic ethnicities (P <0,001 and 0,003). Conclusion: Our study confrms that there is a higher prevalence of fatigue in all the AIDs patients, with comparable VAS scores between IIMs and other AIDs. We can also read our data commenting that females and/or Caucasians patients suffer a higher impact of this manifestation of chronic autoimmune diseases upon their lives. This is why these subjects, to our judgement, should be carefully evaluated during outpatients visits and to whom we should spend some extra time to discuss health related issues and how to improve them.