Religiosity, Spirituality, and Fatigue in Patients With Idiopathic Inflammatory Myopathies: A Brazilian Multicentric Case-Control Study

Background Despite advances in understanding and studying fatigue in idiopathic inflammatory myopathies (IIMs), no studies have addressed the literature that address the influence of religiosity and spirituality on fatigue in IIM patients. Methodology This multicenter, case-control study was conducted at four Brazilian institutions following the STROBE protocol. Data were collected between August 2022 and April 2023 using a semi-structured questionnaire that included sociodemographic information and the Duke University Religion Index (DUREL) with three domains (organizational religious affiliation (ORA), non-organizational religious affiliation (NORA), and intrinsic religiosity (IR)), Attitudes Related to Spirituality Scale (ARES), and Fatigue Severity Scale (FSS). Fatigue was defined as FSS scores ≥36. The sample was not probabilistic due to the rarity of IIMs. The control group was randomly selected from the same city where the case group was selected. Logistic regression was performed with the variables that showed statistical significance in the bivariate analysis. Results The IIM group was positively associated with IR (odds ratio (OR) = 2.70, 95% confidence interval (CI) = 0.20-1.77, p = 0.013), income of less than two minimum wages (OR = 12.21, 95% CI = 1.54-4.02, p < 0.001), between 2 and 4 (OR = 12.52, 95% CI = 1.31-3.73, p < 0.001), and being alone (OR = 0.18, 95% CI = -2.47 to -0.91, p < 0.001) in the multivariate analysis. The presence of fatigue (OR = 3.30, 95% CI = 0.56-1.82, p < 0.001) and comorbidities (OR = 3.36, 95% CI = 0.59-1.83, p < 0.001) were also associated with the case group in logistic regression. The IIM group with fatigue had higher religiosity (ORA, NORA, and IR) levels compared to patients without fatigue. Conclusions IIM with fatigue was associated with the presence of comorbidities, low socioeconomic levels, absence of a partner, and higher levels of religiosity.