Preferences for eye drop characteristics among glaucoma specialists: a willingness-to-pay analysis.
To determine the importance that US glaucoma specialists place on attributes of eye drops for lowering intraocular pressure. We performed a cross-sectional survey by conducting a telephone interview with 113 members of the American Glaucoma Society. We administered a willingness-to-pay (WTP) instrument asking glaucoma specialists how much they would pay to obtain particular characteristics in an eye drop. Demographic data were correlated with the WTP responses. We compared the glaucoma specialists' responses to those previously obtained from patients. The main outcome measure was willingness-to-pay more (in US dollars). Almost all respondents were willing to pay extra to reduce the frequency of administration of eye drops from 3 times a day to once a day, and to avoid blurred vision, drowsiness, or inhibition of sexual performance. Only 54 (48%) were willing to pay more to avoid iris darkening. The mean amount that respondents were willing to pay (relative to US 50 dollars) differed significantly across eye drop characteristics (P < 0.001). The mean amount that the respondents were willing to pay was highest for avoidance of inhibition of sexual performance (US 105 dollars), blurred vision (US 92 dollars), and drowsiness (US 92 dollars). When compared with glaucoma and glaucoma suspect patients, more ophthalmologists were likely to pay extra for desirable eye drop attributes. However, the magnitude of the extra amount was similar between ophthalmologists and patients. Glaucoma specialists place differing value on various eye drop characteristics. Although the proportion of glaucoma specialists willing to pay more is generally greater than the proportion of patients, the preferences of glaucoma specialists and patients are alike.