Reliability and Validity of the Chinese Mandarin Version of the Swallowing Quality of Life Questionnaire

Abstract

Swallowing disorders can adversely affect quality of life (QOL). To develop the Chinese version of the Swallowing Quality of Life Questionnaire (ChSWAL-QOL) and evaluate its reliability and validity, the ChSWAL-QOL was generated by forward translation of the original SWAL-QOL, backward translation, cultural adaptation, and revision using the Delphi method. The ChSWAL-QOL was administered to 376 patients with dysphagia treated at Peking Union Medical College Hospital between November 1, 2017 and December 31, 2018. Reliability was evaluated using Cronbach's α and test-retest reliability. Content validity was assessed using the content validity index (CVI). Structural validity was evaluated by exploratory factor and confirmatory factor analyses. The 44-item, 11-dimension of ChSWAL-QOL was considered semantically relevant, clearly expressed and easy to understand in a preliminary study. The final analysis included 360 of 376 questionnaires (95.7%). Cronbach's α was 0.906 for the whole scale and ranged from 0.815 to 1.000 for the individual dimensions, and the test-retest reliability was 0.847, indicating that the ChSWAL-QOL had excellent internal consistency. CVI was 0.964 overall and ranged from 0.870 to 1.000 for the individual dimensions. Exploratory factor analysis identified a dysphagia-related component (psychological burden, feeding duration, swallowing symptoms, eating desire, communication, feeding fear, mental health, and social function) and a generic component (fatigue and sleep) explaining 52.8% and 10.8% of the variance, respectively. The ChSWAL-QOL has excellent reliability and validity. This scale could be used as a tool to assess the QOL of patients with dysphagia in mainland China.

Keywords: Quality of life; Questionnaire design; Reliability and validity; Swallowing disorders.