Willingness-to-pay for genetic testing for inherited retinal disease

Background: Diagnostic tests are often evaluated according to how the results will change clinical management. Patients may value information even if the management does not change. Objective: To investigate the willingness of adults with inherited retinal disease to undergo and pay for diagnostic genetic testing in three hypothetical scenarios and to explore the factors that influence decision making. Methods: Fifty patients were purposively sampled from an initial cohort of 200 participants and presented with three scenarios whereby genetic testing provided increasing information: (i) confirming the diagnosis and inheritance pattern alone, (ii) providing additional information on future visual function, and (iii) identifying in addition a new treatment which could stabilise their condition. Willingness-to-pay (WTP) was elicited using an iterative bidding game. Regression analysis was used to investigate the probability of agreeing to and paying for testing. Qualitative data were also reviewed to provide a comprehensive understanding of WTP and decision making. Results: The majority of participants agreed to undergo genetic testing in each of the three scenarios. Scenario 2 was the least acceptable with 78% of participants agreeing to genetic testing. The probability of agreeing genetic testing decreased with age. Between 72%-96% of participants reported a WTP for genetic testing. Average WTP was £539, £1,516 and £6,895 for scenarios 1, 2 and 3 respectively. WTP appeared to rise with age and income. Qualitative data provided additional detail about the rationale behind participants’ decisions. Conclusions: The study suggests that patients with inherited retinal disease were willing to undergo and to pay for diagnostic genetic testing, suggesting that they valued the information it may provide. However, several patients preferred not to receive prognostic information and were less willing to pay for genetic testing that yielded such detail.