Translation, validation and cross-cultural adaptation of the Revised Fibromyalgia Impact Questionnaire (FIQR) in Nepali language.

Abstract

To translate, cross-culturally adapt and test the psychometric properties of the Revised Fibromyalgia Impact Questionnaire (FIQR) in Nepali language (Nepali FIQR). The translation was performed following the methodological standards described by Beaton. Comprehensibility testing of the preliminary version was done in 40 fibromyalgia patients, and a pre-final version was prepared after making changes in the original version to maintain the equivalence with the target version. Psychometric testing was done in another group of 130 fibromyalgia patients to test for content validity and reliability. Construct validity was tested with visual analog score (VAS) for pain and Short Form (SF)-36. Nepali FIQR was comprehensible to 92.5% patients. The internal consistency was also acceptable with Cronbach's alpha of 0.900, 0.714 and 0.863 for function, overall and symptoms domain, respectively. Construct validity was also acceptable with a moderate correlation between Nepali FIQR and VAS and SF-36. Test-retest reliability of the total Nepali FIQR and of each item were acceptable with intraclass correlation coefficient (ICC) of >0.7 in all items except for question 1 of function domain (ICC: 0.65). Nepali FIQR is a comprehensible, reliable and valid tool for evaluation of the functional status of Nepalese patients with fibromyalgia and should be implemented in routine clinical care and research settings.