Does the choice of health utility measure affect the incremental cost-utility ratio (ICUR) when assessing the cost-effectiveness of bilateral cochlear implantation (CI)?
Background: CI has revolutionized the management of patients with severe to profound hearing loss. However, its widespread uptake and significant cost mean its health economics are coming under increasing scrutiny. There is a lack of consensus about whether bilateral CI is cost-effective. The key to analyzing cost-effectiveness is measuring clinical utility.
Explore This IssueFebruary 2015
Study design: A scenario-based estimate with three scenarios given to 142 subjects between 2008 and 2010.
Setting: Sunnybrook Cochlear Implant Clinic, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.
Synopsis: Four utility indexes were used: Health Utility Index Mark 3 (HUI3), European Quality of Life Questionnaire in 5 Domains (EQ5D), visual analog scale (VAS), and time trade-off (TTO). For 52 professionals and members of the Canadian Cochlear Implant Group, three scenarios were presented: 1) a patient with severe to profound sensorineural hearing loss with no intervention, 2) the same patient with a unilateral CI with average or better performance, and 3) the same patient with bilateral CIs with average or better performance. Ninety patients were divided into three groups with postlingual deafness: 1) severe to profound hearing loss eligible for a CI, 2) unilateral CI recipients with at least one year of implant use and a mean Hearing in Noise Test (HINT) score of >80% in quiet, and 3) bilateral CI recipients with at least one year of implant use in either ear and a mean HINT score of >80% in quiet. Using the HUI3, the utility measure across all groups was 0.495 for no intervention, 0.765 for unilateral implantation, and 0.8 for bilateral intervention. Using the EQ5D tool, the utility measure was 0.75 for no intervention, 0.89 for unilateral implantation, and 0.93 for bilateral intervention. Using the VAS tool, the utility measure was 0.68 for no intervention, 0.81 for unilateral implantation, and 0.88 for bilateral intervention. Using TTO, the utility measure was 0.65 for no intervention, 0.82 for unilateral implantation, and 0.94 for bilateral intervention. Although the HUI3 specifically addresses hearing and speech deficits, it is prone to bias by individuals with hearing loss or those treating hearing loss.
Bottom line: Utility instrument choice for cost-utility analysis of bilateral CI heavily influences whether the second implant is deemed cost-effective. The HUI3 is the most conservative and the least likely to overestimate the cost utility of a second CI.