The Willingness to Pay for the Prevention of Visual Impairment Among Community Members

Abstract

 

Purpose:

 

We estimated the willingness to pay (WTP) to avoid loss of visual function in people with diabetic macular edema (DME) using a discrete choice experiment (DCE), a method developed by market researchers.

 

Methods:

 

Patients with DME were recruited for focus groups to identify important attributes of daily living. We prioritized these attributes by conducting a DCE with 52 people with DME or diabetic retinopathy from whom we received 33 valid responses. The top 9 attributes identified from this DCE were used to construct the WTP DCE in which scenarios describing "insurance policies" offered a 100% guarantee that the participant would never experience functional loss worse than what was described in the scenario. Attributes were presented in three levels of difficulty ranging from "never a problem" to "always a problem". Premiums ranged from $60 to $12,000/year. Each respondent chose between two scenarios consisting of five attributes selected from the 9; all included an insurance premium. We present preliminary results from 152 participants who completed the WTP DCE. Utilities were estimated using multinomial logit regression and a demand curve for the "purchase" of visual function was fitted.

 

Results:

 

The nine attributes identified were ocular pain, ability to leave home, ability to drive during the day, seeing well up close, difficulty with visual aids, needing help with daily tasks, fear of falling, distance vision, and being able to read. See the Table for our WTP estimates. WTP to avoid the worst vision state ranged from $4,814 for severe ocular pain to $615 for severe frustration with visual aids. WTP to avoid severe loss of all functions totaled $19,825. Within an attribute (not shown) WTP increased exponentially with more severe loss of function.

 

Conclusions:

 

We have demonstrated the high value placed on preserving visual function in a community based sample. Future work in this project will consider how the preference for these attributes differ between people with DME and community based participants.  

 

Keywords: quality of life • diabetic retinopathy • edema