The validity and reliability of the Turkish version of the Revised Fibromyalgia Impact Questionnaire

The Revised Fibromyalgia Impact Questionnaire (FIQR) attempts to address the limitations of the Fibromyalgia Impact Questionnaire (FIQ). As there is no Turkish version of the FIQR available, we aimed to investigate the validity and reliability of a Turkish translation of the FIQR in Turkish female fibromyalgia (FM) patients. After translating the FIQR into Turkish, it was administered to 87 female patients with FM. All of the patients filled out the questionnaire together with a Turkish version of the FIQ, hospital anxiety and depression scales (HADS), short form-36 (SF-36). The tender-point count (TPC) was also calculated from tender points identified by thumb palpation. One week later, FM patients filled out the Turkish FIQR at their second visit. The test-retest reliability of the Turkish FIQR questions ranged from 0.714 to 0.898. The test and retest reliability of total FIQR score was 0.835. Cronbach's alpha was 0.89 for FIQR visit 1 (the first assessment) and 0.91 for FIQR visit 2 (the second assessment), indicating acceptable levels of internal consistency for both assessments. The total scores of the FIQR and FIQ were significantly correlated (r = 0.87, P < 0.01). Significant correlations for construct validity were also obtained between the FIQR total and domain scores and the FIQ, the HADS and the subscales of the SF-36 (FIQR total versus SF-36 physical component score and mental component score were r = -0.63, P < 0.01 and r = -0.51, P < 0.01, respectively). The Turkish FIQR is a reliable and valid instrument for measuring health status in FM, showing sufficient reliability and construct validity. It may be utilized for both clinical practice and research use in the Turkish-speaking population in place of FIQ, since its Turkish version has problems in the wording, omissions, concepts, and scoring from the original FIQ.