The direct costs to the Canadian Ministry of Health were included to come up with the total cost for unilateral and bilateral implants—from the cost of the system itself to the price discount given for the second side to an expected failure rate of 15 percent. The analysis considered a service provision of 25 years. This cost was used as the base case, and sensitivity analyses were performed to determine cost as cases deviated from the base case.
Three groups were compared: those who were deaf, with no intervention; those with a unilateral implant, at a cost of $63,622; and those with a bilateral implant, at a cost of $111,764. The utility of the implants was assessed using four methods; the most conservative, and therefore the least likely to overestimate the cost utility of bilateral implants, was the Health Utility Index (HUI-3). The research team found that moving from unilateral to bilateral implantation added only 12 percent to the overall utility seen from moving from no intervention to bilateral.
The implant groups’ cost utility was compared using the Incremental Cost Utility Ratio, or the change in cost over the change in utility. The cost utility of a unilateral implant compared with no intervention was found to be $14,658 per QALY, with a range of $10,000 to $19,000, using the HUI-3. The cost utility of bilateral implant compared with a unilateral was $55,020 per QALY, with “lesser cost” but also “much lesser gain.”