1. 2019;22;E511-E516Fibromyalgia Impact Score in Women with Fibromyalgia Across Southern, Central, and Northern Areas of Europe
   Observational Study
   C. Paul van Wilgen, PhD, Manuel Delgado-Fernandez, PhD, Kaisa Mannerkorpi, PhD, Jo Nijs, PT, PhD, Inmaculada C. Alvarez-Gallardo, PhD, Pedro Jesus Ruiz-Montero, PhD, and Victor Segura-Jimenez, PhD.

BACKGROUND: The Fibromyalgia Impact Questionnaire (FIQ) is the most used questionnaire worldwide to measure the health status of patients with fibromyalgia. The questionnaire has been subjected to several studies to analyze psychometric properties. However, norm scores and cultural differences have not been presented.

OBJECTIVES: To obtain and present norm scores for the FIQ in patients with fibromyalgia in different cultures, namely Southern, Central, and Northern areas of Europe.

STUDY DESIGN: This observational study consisted of women with fibromyalgia from 4 countries (Spain, Belgium, the Netherlands, and Sweden) classified in 3 areas (Southern, Central, and Northern) in Europe.

SETTING: Women with fibromyalgia from Spain, Belgium, the Netherlands, and Sweden.

METHODS: The impact of fibromyalgia was assessed by the FIQ. A total of 1,478 women with fibromyalgia were asked to fill out the FIQ in the Spanish (n = 531), Dutch and Belgian (n = 629), or Swedish (n = 318) versions.

RESULTS: The norm scores and percentiles score of the FIQ are presented. Norm scores differed between European areas (Southern area = 64.8 ± 15.9; Central area = 60.9 ± 15.7; Northern area = 62.8 ± 16.7). Perceived physical impairment, overall well-being (all, P < 0.001), FIQ total (P < 0.01), and morning tiredness (P < 0.05) in women with fibromyalgia from the Central area of Europe reported lower impact than Southern and Northern areas. The Northern area of Europe showed the lowest score of job difficulty, anxiety, depression (all, P < 0.001), and pain (P < 0.01), whereas the Southern area of Europe showed the lowest score of work missed subscale (P < 0.001) with regard to the rest of the areas studied.

LIMITATIONS: The selection of patients was conducted with just women because of the scarce prevalence of fibromyalgia among men. Moreover, sociodemographic status, socioeconomic status, and clinical characteristics were not measured. Similar research should be conducted with adequate representation of populations from other parts of the world.

CONCLUSIONS: Pairwise comparisons showed significant differences mainly between the Southern area versus Northern and Central areas of Europe. The impact of fibromyalgia showed mainly higher scores in women with fibromyalgia from the Southern area of Europe.

KEY WORDS: Symptom, psychometric, norm scores, European comparison