Psychometric Properties of the Spanish Version of the Swallowing Quality of Life Questionnaire in Fibromyalgia Patients

Abstract

Background and Purpose: The Swallowing Quality of Life Questionnaire (SWAL-QoL) is recognized as the gold-standard instrument for assessing the impact of dysphagia on health-related quality of life (HRQoL). However, a validated Spanish version is currently unavailable. Therefore, the aim of this study was to evaluate the psychometric properties of the Spanish adaptation of the SWAL-QoL (SSWAL-QoL) in fibromyalgia patients. Materials and Methods: A cross-sectional study was completed. Participants completed the SSWAL-QoL, the Spanish version of Hospital Anxiety and Depression Scale (HADS), the Spanish version of Short Form12 (SF12), the Spanish version of EQ-5D-3L, and the Spanish version of the Impact Fibromyalgia Questionnaire (FIQ). Construct validity, evaluated through Exploratory Factor Analysis and correlations with related measures, and reliability, estimated via internal consistency, were found to be adequate for the SSWALQoL. Results: The results indicated that the psychometric properties of the SSWAL-QoL are adequate and comparable to those of the original instrument. The result of Bartlett’s test of sphericity was 970.573 (df = 55, p < 0.001), and the value of the Kaiser–Meyer–Olkin (KMO) measure of sampling adequacy was 0.857. A total of two factors could be extracted. The reliability was high for the total subscales of the SSWAL-QoL. Differences were found between groups in all included outcomes. Conclusions: The SSWAL-QoL demonstrates satisfactory psychometric properties for its use in a Spanish-speaking population with fibromyalgia. As the first validation of this instrument in this specific population, it provides clinicians and researchers with a reliable and valid tool to assess the impact of dysphagia on HRQoL.