A Validation Study on the Filipino Geriatric Depression Scale (GDS) using Rasch Analysis
Document Type
Article
Publication Date
2019
Abstract
At present, there is a dearth of studies that assess the “cultural equivalence” and dimensionality of the Filipino translated Geriatric Depression Scale (GDS) using item response theory methods. Using the Rasch model, this study sought to evaluate a Filipino-translation of GDS items using two parameters--one for ability to each person, and another for difficulty to each item. Doing so overcomes a source of continuing controversy associated with Likert scales. A total of 505 elderly respondents participated in the study. Results provided support that the 30 Filipino translated items form a unidimensional measure of depressive mood, as shown by their acceptable fit statistics; and hence, can be used in research as a valid, interval-level measure of depression. Subsequent Rasch analyses performed also revealed that 18 of 30 items were functioning equally across the two languages, and, of the 18 items, 3 items that assessed anxiety were dropped thereby creating a Filipino GDS Short Form (GDS-SF-F) that obeyed the requirements of the Rasch model, while conforming to the content of depression as given in the DSM-5. The study concludes that the 15-item GDS-SF-F can be used as a short measure of depression that provides a genuine interval level of measurement, with adequate internal consistency
Recommended Citation
Welison Evenston G Ty, Roger D Davis, Maria Isabel E Melgar, et al. A Validation Study on the Filipino Geriatric Depression Scale (GDS) using Rasch Analysis. Int J Psychiatr Res. 2019; 2(7): 1-6
