Cross-Cultural Adaptation and Validation of the SWAL-QoL Questionnaire in Greek

The purpose of this study was to translate and adapt the 44-item SWAL-QoL into Greek and examine its internal consistency, test-retest reliability, external construct validity, and discriminant validity in order to provide a validated dysphagia-specific QoL instrument in the Greek language. The instrument was translated into Greek using the back translation to ensure linguistic validity and was culturally adapted resulting in the SWAL-QoL-GR. Two groups of participants were included: a patient group of 86 adults (48 males; age range: 18-87 years) diagnosed with oropharyngeal dysphagia, and an age-matched healthy control group (39 adults; 19 males; age range: 18-84 years). The Greek 30-item version of the WHOQOL-BREF was used for assessment of construct validity. Overall, the questionnaire achieved good to excellent psychometric values. Internal consistency of all 10 subscales and the physical symptoms scale of the SWAL-QoL-GR assessed by Cronbach's α was good to excellent (0.811 < α < 0.940). Test-retest validity was found to be good to excellent as well. In addition, moderate to strong correlations were found between seven of the ten subscales of the SWAL-QoL-GR with limited items of the WHOQΟL-BREF (0.401 < ρ < 0.65), supporting good construct validity of the SWAL-QoL-GR. The SWAL-QoL-GR also correctly differentiated between patients with dysphagia and age-matched healthy controls (p < 0.001) on all 11 scales, further indicating excellent discriminant validity. Finally, no significant differences were found between the two sexes. This cultural adaptation and validation allows the use of this tool in Greece, further enhancing our clinical and scientific efforts to increase the evidence-based practice resources for dysphagia rehabilitation in Greece.