Psychometric Evaluation of the Urdu Version of the Glaucoma symptom scale: Assessing Its Reliability and Validity in Low-Literacy Populations
DOI:
https://doi.org/10.71000/dzaegm77Keywords:
Low Vision, Quality of Life, NEI-VFQ-25, Psychometric Evaluation, Urdu TranslationAbstract
Purpose: This paper aimed to accomplish the task of translating and validating the Glaucoma Symptom Scale (GSS) in the Urdu language with the prospect of using it with the populace of glaucoma victims in Pakistan.
Methods: Sixty-seven clinically diagnosed patients of glaucoma of the age group 25 to 60 years old were enrolled. There was an assessment of clinical and demographic data. All the respondents were taken through the Urdu version of GSS which constitutes a total of 10 symptom items with two subscales SYMP-6 (non-ocular symptoms) and FUNC-4 (visual capability). The translation was done according to classical forward-backward practice. Classical Test Theory (CTT) was applied in the analysis of psychometric properties of the Urdu GSS, comprising of internal reliability (Cronbachs alpha), test-retest stability (interclass correlation coefficients), and convergent validity through the relationship of the variables with the relevant subscales of SF-36 health survey.
Results: The Urdu version of the GSS was characterized by high levels of internal consistency of the entire scale ( = 0.81). Factor analysis confirmed two-factor design as supported by the scale with 48.92 variance. Overall and subscale GSS scores were found to have significant relationships with clinical indicators of disease severity and with respective SF-36 domains, which confirm convergent validity. There were a few items that had minimal floor and ceiling effects.
Conclusion: Urdu translated version of the Glaucoma Symptom Scale is a valid and reliable tool when discussed with Classical Test theory. It can be successfully employed in determining the symptom burden and quality of life related to vision among the patients of glaucoma who speak Urdu. It is hoped that further research will be done to ascertain its use in other clinical environments.
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