Validation of a quality of life questionnaire in the Pacific Island

Purpose: To adapt an existing validated quality of life instrument, the Impact of Vision Impairment (IVI) questionnaire for Pacific Island countries. Methods: Following in-depth interviews (n=24) and a pilot study (n=67), the original 32-item IVI questionnaire was translated and adapted in Vanuatu. The Melanesian IVI (IVI-M) was administered to participants not previously involved in the pilot study (n=189). Results: Participants included 117 (62%) with mild, moderate or severe vision impairment, 39 with unilateral loss and 33 with normal vision. Eighty-six percent of the original 32-items were deemed relevant by 90% of participants. Items displaying floor effects were removed (4), 2 were combined and 3 items rephrased to reflect Melanesian-specific activities, resulting in a 23-item IVI-M. Nineteen items were relevant to both the Melanesian and Australian contexts including all 8 items related to the emotional reaction to vision loss. IVI-M demonstrated content and construct validity, reliability and discriminated visually healthy populations from those with vision impairment. Vision impairment of <6/18 negatively effected quality of life. Conclusion: While the adaptation process demonstrated the need for culturally relevant instruments, it also highlighted the value of adapting existing validated instrument for use in cross-cultural research rather than developing a new instrument from first principles.