Evaluation of Ankylosing Spondylitis Quality of Life (EASi-QoL) questionnaire: translation, cultural adaptation and psychometric validation for use in Iraqi ankylosing spondylitis patients
摘要
Ankylosing spondylitis (AS) is a chronic autoimmune disease of the axial skeleton that usually starts at early adulthood. Therefore, AS could greatly affect patients’ quality of life. There are scales that assess the quality of life of AS patients, but not in Arabic. Therefore, this study was conducted with the aim of Arabic translation and psychometric validation of the Evaluation of Ankylosing Spondylitis Quality of Life (EASi-QoL) scale.
MethodsA sample of 125 patients was used in this study. Translation followed the general guidelines of forward–backward translation with expert committee review and pilot testing with 10 patients. Validity testing comprised face validity with 15 patients through face validity indices (FVI), content validity with a panel of 15 experts through content validity indices (CVI), and content validity through confirmatory factor analysis (CFA) using a 4-factor model. Reliability testing included calculating Cronbach’s alpha and composite reliability (CR). CFA and reliability testing were performed with data from 100 patients.
ResultsThe translation process involved performing minor changes to adapt the translated EASi-QoL to Arabic speaking AS patients. All face validity indices whether for individual questions or the entire translations exceeded their corresponding threshold indicating good face validity. The same applies for CVI where all indices exceeded 0.8 showing acceptable to good content validity in terms of both relevance and clarity of questions. Regarding CFA, all factor loadings were higher than 0.5 and 4 of 5 fit indices were within acceptable limits demonstrating good model fit. Cronbach’s alpha and CR for the 4 factors were all higher than 0.8 proving good internal consistency of the translated version.
ConclusionsResults from this study provide a valid and reliable Arabic version of EASi-QoL that can be used by clinicians to guide better treatment choices and to provide monitoring options of disease prognosis.