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

This study was undertaken to translate and adapt the Fibromyalgia Impact Questionnaire (FIQ) into the Turkish language and investigate its validity and reliability for Turkish female fibromyalgia (FM) patients. After translation into Turkish, we administered the FIQ and Health Assessment Questionnaire (HAQ) to 51 women with fibromyalgia. As well as socio-demographic characteristics, the severity of relevant clinical symptoms, e.g., pain intensity, fatigue, and sleep disturbance, were assessed by visual analog scales. A tender point score (TPS) was calculated from tender points conducted by thumb palpation. Test–retest reliability, internal consistency, and concurrent and construct validities of FIQ were evaluated. Test–retest reliability and internal consistency were good at 0.81 and 0.72, respectively. Correlation between FIQ and HAQ scores was 0.43, which was low but statistically significant. Significant moderate correlations were obtained between the FIQ items and severity of clinical symptoms (0.63–0.77), except TPS, 0.31. The FIQ is a reliable and valid instrument for measuring functional disability in Turkish female FM patients.