Objective: The objectives of this study were to develop a cross-culturally adapted, Filipino version of the Ocular Surface Disease Index (OSDI) questionnaire and to assess its reliability.
Methods: A Filipino-adapted version of the OSDI was developed following guidelines for language-specific questionnaires: forward translation into Filipino by 2 independent bilingual translators, back-translation into English by a language institution, and a final forward translation to Filipino resolved by a review committee. To check for equivalence, the English and Filipino versions of the OSDI were pretested on 16 patients in a dry eye clinic. The Filipino version was then administered to 36 participants, and a Cronbach alpha coefficient for reliability of the overall instrument and the alpha that would result if each item were removed were computed. Finally, the questionnaire was then retested on 11 dry eye patients to see if the coefficient would increase.
Results: All reported no difficulty with the Filipino questionnaire, with 81.3% expressing preference in answering it. Most (81.3%) chose the same answer in at least half of the items in both languages, though the range of similar responses varied from 41.7% to 91.7%. Reliability testing of the Filipino questionnaire showed this to have fair internal consistency (α=0.5958). The value increased to moderate internal consistency (0.7576) when 3 items were removed.
Conclusion: A culturally-adapted OSDI in Filipino was successfully produced and was the preferred tool by most patient participants.
Keywords: dry eye, dry eye syndrome, dry eye screening, Ocular Surface Disease Index, OSDI, Filipino questionnaire