Validity and Reliability of the Persian Version of Revised Fibromyalgia Impact Questionnaire in Iranian Patients with Fibromyalgia

Background and Fibromyalgia (FM) is a chronic pain condition with non-articular origin that is defined by generalized pain, fatigue and sleep disturbance. The aim of this study was to evaluate the reliability and validity of Persian version of Revised Fibromyalgia Impact Question­naire (FIQR) in Iranian patients with FM.
The FIQR was translated into Persian and adminis­tered to 44 female patients with primary FM. All patients filled out the questionnaire along with the Persian version of the Hospital Anxiety and Depression Scale (HADS) and short form-36 (SF-36). One week later, FM patients filled out the FIQR at their second visit. Reliability was analyzed by internal consistency Cronbach’s α coefficient and intra-class correlation coefficient. Construct validity was evalu­ated by Spearman’s and Pearson’s correlation coefficient. Statistical analysis was performed in SPSS ver. 19.
From 69 female patients with primary FM who had HADS score less than 15, 44 were selected. The total scores of the FIQR in first and second visits were 52.85±20.2 and 53.62±18.3, respectively. Evaluation of construct validity with SF-36 and HADS showed a significant correlation at the 0.01 level. The intraclass correlation coefficient (ICC) was CI95%=0.929 (0.896-0.956) and Cronbach’s α was 0.93 for FIQR in the first visit. The correlation between first and second total scores was 0.82 (P=0.001).
The Persian version of FIQR showed adequate reliability and validity.