Validation of the Arabic Version of the Fibromyalgia Survey Questionnaire.

Introduction: Fibromyalgia is a prevalent rheumatological condition that is marked by pervasive and widespread body discomfort. The diagnosis of Fibromyalgia can be challenging. For this reason, the American College of Rheumatology developed a scoring system, the Fibromyalgia Survey Questionnaire (FSQ). To address the lack of validated scales in the Arabic language for assessing fibromyalgia, this study aimed to examine the psychometric properties of the Arabic-language version of the FSQ in two Arabic-speaking populations (Lebanon and Palestine).

Methods: Our study followed cross-sectional design. It was conducted from October 2024 to January 2025, within a period of five months, enrolling Lebanese and Palestinian adults. The questionnaire included sociodemographic questions and scales including the Widespread Pain Index (WPI), Symptom Severity Scale (SSS), Patient Health Questionnaire (PHQ-4) and Insomnia Severity Index (ISI).

Results: In total, 1148 participants participated in this study, with a mean age of 29.11 ± 12.50 years and 66.90% females. Among them, 58 (5.05%) were identified as having a possible diagnosis of fibromyalgia. The fit indices of the FSQ and SSS scales were acceptable after adding correlations between items. Internal reliability was adequate for the total scale in the total sample, in Lebanese and Palestinian samples for both scales. Invariance was shown at the metric and scalar levels in terms of genders and countries for both scales. A significantly higher mean LOG WPI and LOG SSS was found in females compared to males. No significant difference was found between Lebanese and Palestinian participants in terms of WPI; however, Lebanese scored higher SSS scores compared to Palestinians. Higher WPI and SSS scores were significantly associated with higher anxiety, depression and insomnia.

Conclusion: This study supports the reliability and validity of the Arabic versions of the FSQ as robust measures for fibromyalgia. Adequate internal consistency, model fit, concurrent validity, and measurement invariance suggest that the Arabic scale is valid to utilize in both clinical and research settings.