The Chinese Version Of The Glaucoma Symptom Scale Questionnaire: Translation,Validity,and Reliability

Objective This study aims to introduce the English version of the Glaucoma Symptom Scale Questionnaire(GSS),and form a Chinese version of the GSS questionnaire based on translation,back-translation,cross-cultural adaptation,reliability and validity testing,etc.,so as to test the applicability of the GSS questionnaire for glaucoma patients and provide an effective survey tool for evaluating and screening the symptoms of glaucoma patients in China.Methods The copyright of GSS questionnaire for translation was licensed by purchasing from the publisher.The English version of the GSS questionnaire was localized according to the Brislin translation model,and the Chinese version of the GSS questionnaire was formed after cross-cultural adaptation and pre-experiment revision.A total of 205 glaucoma patients from three hospitals in Hefei were investigated with the by convenience sampling method and the results were analyzed by EXCEL and SPSS.The authority degree of experts is calculated through expert consultation.The items of the Chinese version of GSS were analyzed by four methods including correlation coefficient method,critical ratio method,answer distribution analysis method and Cronbach’s α method.The reliability of the Chinese version of GSS was tested using Cronbach’s α coefficient,splithalf reliability and test-retest reliability.The validity of the GSS was evaluated by content validity and construct validity.Receiver Operating Characteristic(ROC)curve was drawn to evaluate the predictive ability of the Chinese version of the GSS questionnaire,and to determine the sensitivity,specificity and the most appropriate critical value of GSS.The consistency of Chinese version of GSS scale and clinicians’ judgment was analyzed by criterion-related validation,and the correlation between the Chinese version of GSS scale and NEI-VFQ-25 was also compared.Results The value of familiarity coefficient(Cs),judgment coefficient(Ca),and authority coefficient(Cr)were 0.806,0.950 and 0.878,respectively.The Kendall harmony coefficients of the two rounds of expert consultation were 0.662 and 0.756,respectively(P<0.01).The value of S-CVI,I-CVI were both 1.The KMO of 205 samples was 0.829 after exploratory factor analysis,which was greater than 0.6.The Bartlett spherical detection value was 526.783(P<0.001).On the premise of not limiting the number of factors,two common factors with eigenvalues greater than 1 were extracted by principal component analysis and maximum variance method,combined with scree plot test,and the cumulative variance contribution rate was 50.641%.Taking clinician’s diagnosis as the gold standard,the area under the ROC curve of GSS scale was 0.916(95CI%=0.886-0.947,P<0.01).The optimal critical score of the scale was 73,and the sensitivity and specificity were 0.852 and 0.873,respectively.The positive prediction rate was 0.877,the negative prediction rate was 0.847,and the Uden index was 0.725.At this time,the concordant Kappa value of the two diagnostic results was 0.749(P < 0.001).The average values of the GSS scores were similar for the glaucoma patients of all levels distinguished by the standard visual field examination and there was no significant difference in the scores of the glaucoma patients of all levels after the univariate ANOVA comparison of mean analysis(P>0.05).The Cronbach’s α coefficients of the Chinese version of GSS and the two subscales were 0.812,0.721 and 0.708,respectively,and the splithalf reliability coefficients were 0.781,0.679 and 0.639,respectively.Two weeks later,30 glaucoma patients were retested.The retest reliability of the Chinese version of GSS scale,SYMP-6 subscale and FUNC-4 subscale were 0.912,0.886 and 0.909,respectively.Conclusion 1.The Chinese version of the GSS questionnaire has good reliability and validity,and is suitable for the measurement of glaucoma patients in China;2.The GSS questionnaire has good practicability,easy-to-understand items,and the completion time can be controlled within 10 minutes;3.The Chinese version of GSS questionnaire has a good diagnostic value for glaucoma,but it cannot distinguish the severity of glaucoma.