Patient preferences for diabetic retinopathy health States.

PURPOSE. To develop standardized descriptions of health states that characterize vision-specific functional impacts of diabetic retinopathy (DR) according to levels of visual acuity and contrast sensitivity and to elicit preferences for these health states from persons with DR and assign weighted values to them. METHODS. Vision-specific descriptions of health states were developed based on a literature review and patient and physician interviews. The content was based on items from the National Eye Institute Visual Functioning Questionnaire (VFQ) and reflected functional impacts experienced by DR patients. Values were assigned to the range of health states, anchored by the extremes full vision and death, by using the time-tradeoff method in a sample of 98 Canadian DR patients from three clinical centers. RESULTS. The mean age of the sample was 60.4 years, and 56% were men. Mean preferences decreased from 0.98 (better-eye logMAR [Snellen equivalent] acuity, > or =20/40; worse-eye Snellen equivalent, > or =20/200) to 0.67 (Snellen equivalent visual acuity, < or =20/200, contrast sensitivity, < or =21 letters bilaterally). Preferences decreased with increasing severity of functional deficits and did not vary significantly by sex, age, VFQ quartile, or better- or worse-eye acuity. CONCLUSIONS. This is the first study that has been conducted to estimate preferences for standardized DR-specific health states, accounting for visual acuity and contrast sensitivity in both eyes. The results showed that the development and progression of DR are associated with substantial declines in preferences. In addition to the progressively greater impact from declining ETDRS visual acuity and contrast sensitivity, preference weights declined with increasing bilateral disparity. These preference values are useful for comparing the cost effectiveness of ophthalmic treatments.