Cross-cultural adaptation and validation of the Korean fibromyalgia impact questionnaire in women patients with fibromyalgia for clinical research

Our aim was to translate and cross-culturally adapt the fibromyalgia impact questionnaire into Korean (KFIQ), and then evaluate its reliability and validity. The FIQ was translated into Korean by three translators and then independently translated back into English by three different translators. A total of 62 women patients with fibromyalgia (FM) were studied for the psychometric properties of the KFIQ. The mean age of the patients was 47.1 (25–73) years, and all were female. The mean KFIQ score was 48.3 (17–91), and the mean Korean health assessment questionnaire (KHAQ) score was 0.4 (0–1.7). The test–retest reliability of the KFIQ yielded an intraclass correlation coefficient of 0.85 (0.53–0.96). For the construct validity, the Spearman rank correlations of KFIQ with patient global assessments using visual analog scale (pain, 0.58; morning stiffness, 0.45; fatigue, 0.48; depression, 0.43; anxiety, 0.56; global well-being, 0.46; disease severity, 0.49; impact on life, 0.51), KHAQ (0.44), and tender points (0.60) were high and statistically significant. The KFIQ might be a reliable and valid instrument for measuring health status and physical functioning in Korean women patients with FM, but needs further study.