Abstract
Purpose :
A major international project is underway to develop and validate item banks for the comprehensive measurement of quality of life (QOL) all eye diseases (the Eye-tem Bank).
Methods :
14 disease-specific item banks are being developed. We employ a systematic 4-phase method for the development of each disease-specific modules: Phase I: Content identification (items from existing instruments and disease-specific patient focus groups); Phase II: Pilot testing the initial item sets for item calibration using Rasch analysis; Phase III: Validation of the module-specific CAT system; and Phase IV: Evaluating ophthalmic QOL.
Results :
Phase I (Australia, n=780, median age, 56.5 yrs; Nepal, n=101, median age, 29 yrs ; India, n=30, median age, 33 yrs) has identified 3226 unique items for 7 modules across 8 to 11 ophthalmic QoL domains (activity limitation, mobility, visual symptoms, ocular comfort symptoms, general symptoms, convenience, concerns, social, emotional, economic and coping). Overall 30-50% of items are common between modules and 60-79% between countries. Phase II has been completed for glaucoma (n=293), diabetic retinopathy (DR, n=514) and hereditary retinal disease (HRD, n=233) in Australia; and refractive error (n=301) in Nepal. Phase II is ongoing for age-related macular degeneration (n= 100), acquired retinal diseases (n=20), refractive error (Australia, n=85) and amblyopia & strabismus (India, n=101, Australia, n=15). Items of 4 modules (glaucoma, HRD, DR and refractive error (Nepal)) have been calibrated using Rasch analysis. Phase III data collection for DR module is ongoing in Singapore (n=40). Four new domains of QoL (driving, lighting, coping and treatment-related convenience) have emerged. Items are being extracted and refined using qualitative methods to develop cornea (n=41), retinal detachment (n=39), uveitis spectrum of diseases (n=41), and inflammation (n=39)-specific pilot item banks.
Conclusions :
Comprehensive item banks for disease-specific QoL have been created. Disease-specificity appears important with only one-third of items common across disease modules. Internationalisation appears viable with more than two-thirds of items common across countries. A core universal item set common to modules and countries will be developed and tested.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.