Functioning in the fibromyalgia syndrome: validity and reliability of the WHODAS 2.0

Abstract

Background Fibromyalgia syndrome (FMS) is both a challenging and disabling condition. The International Association for the Study of Pain (IASP) classifies FMS as chronic primary pain, and it can negatively impact individuals’ functioning including social, psychological, physical and work-related factors. Notably, while guidelines recommend a biopsychosocial approach for managing chronic pain conditions, FMS assessment remains clinical. The WHODAS 2.0 is a unified scale to measure disability in the light of the International Classification of Functioning, Disability and Health. Thus, this study aimed to evaluate the reliability and validity of the Brazilian version of WHODAS 2.0 for use in individuals with FMS. Methods Methodological study of the validity and reliability of the Brazilian version of the 36-item WHODAS 2.0 with 110 individuals with FMS. The instrument gives a score from 0 to 100, the higher the value, the worse the level of functioning. We assessed participants with Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) (0–100), Fibromyalgia Impact Questionnaire (FIQ) (0–10) and Beck Depression Inventory instrument (BDI) (0–63). The construct validity, internal consistency, and test–retest stability. We used SF-36, FIQ and BDI to study construct validity analysis. For statistical analysis, we performed the intraclass correlation (ICC), Spearman correlation, and Cronbach's alpha, with a statistical level of 5%. Results Most participants were female (92.27%), aged 45 (± 15) years. The test–retest reliability analysis (n = 50) showed stability of the instrument (ICC = 0.54; ρ = 0.84, p < 0.05). The test–retest correlation between the domains was moderate to strong (ρ > 0.58 and < 0.90). Internal consistency was satisfactory for total WHODAS 2.0 (0.91) and also for domains, ranging from 0.44 to 0.81. The construct validity showed satisfactory values with all moderately correlated with WHODAS 2.0 instruments (> 0.46 and < 0.64; p < 0.05). WHODAS 2.0 evaluates the functioning encompassing components of health-related quality of life, functional impact, and depressive symptoms in those with FMS. Conclusions WHODAS 2.0 is a reliable and valid instrument to evaluate functioning of Brazilians with FMS. It provides reliable information on individuals' health through of a multidimensional perspective, that allows for individual-centered care.

Active and sham transcranial direct current stimulation (tDCS) improved quality of life in female patients with fibromyalgia

“…The above results should be interpreted in the light of a number of limitations. First, the FIQ-R does not provide a complete profile of the functioning of patients with FM; thus, future research should include specific indices of functioning such as the WHODAS 2.0 [85]. Second, the design of our study may make it difficult to differentiate between the effect of tDCS itself and the effect of the intervention.…”

Psychometric properties of Polish version of the 36-item WHODAS 2.0 in individuals with fibromyalgia

“…for the test-retest reliability of the 36-item WHODAS 2.0 in individuals with FM were also obtained by Barreto et al 19 , although their study showed less stability in the domains of activity and participation. Other authors investigating the repeatability of measurements by means of the 36-item WHODAS 2.0 in different groups of patients with chronic diseases con rmed its very good test-retest reliability 36,37 .…”

“…The internal consistency of the 36-item WHODAS 2.0 was assessed using the Cronbach's Alpha coe cient, which was 0.95 for the total score, indicating high reliability of the scale. The Cronbach's Alpha coe cient for the 36-item WHODAS 2.0 in the Brazilian population was 0.91 19 . In other studies evaluating the psychometric properties of the 36-item WHODAS 2.0 in rheumatic or chronic diseases, authors also con rmed very good internal consistency of the tool 36,37 .…”

“…The 36-item WHODAS 2.0 is a universal tool used to assess disability in individuals with various health conditions 24,25,36,37 . So far, only one study in the world has evaluated the psychometric properties of the 36-item WHODAS 2.0 in people with FM 19 . WHO recommends the use of the 36-item WHODAS 2.0 in the new revision of ICD-11.…”