Identification and Evaluation of Items for Vitreoretinal Diseases Quality of Life Item Banks.

Purpose: We are developing item banks assessing the impact of retinal and vitreoretinal diseases (excluding age-related macular degeneration, diabetic retinopathy, and retinal detachment, covered elsewhere) on quality of life (QoL) for adults. This study outlines the first two phases of the multi-stage process: content development and item evaluation.

Methods

We grouped retinal and vitreoretinal diseases into hereditary and acquired. Development of the item banks involved two phases: item identification and item evaluation. The items were extracted from three sources: (1) 17 pre-existing PRO instruments, (2) 4 qualitative studies and (3) 79 semi-structured interviews. Item evaluation involved three stages namely, binning (grouping) and winnowing (reduction), expert panel opinion and cognitive interviews.

Results

The item identification phase yielded 1,217 items. After three sessions of binning and winnowing, items were reduced to a minimally representative set (n = 411) across nine QoL domains namely, activity limitation, emotional, social, health concerns, symptoms, economic, mobility, convenience, and coping. The hereditary group had a total of 345 items and the acquired group had a total of 257 items. After 23 cognitive interviews items were amended for hereditary diseases resulting in a final set of 345 items and 3 items were amended for acquired diseases, resulting in a final set of 254 items. Overall across nine domains 189 items were common to hereditary and acquired retinal and vitreoretinal diseases.

Conclusion

As most of the items were unique to hereditary versus acquired retinal and vitreoretinal disease groups separate item banks are required to capture the QoL impacts for hereditary and acquired retinal and vitreoretinal diseases.