Bilateral Cochlear Implantation: A Health Technology Assessment.

backgroundSensorineural hearing loss occurs as a result of damage to the hair cells in the cochlea, or to the auditory nerve. It negatively affects learning and development in children, and employment and economic attainment in adults. Current policy in Ontario is to provide unilateral cochlear implantation for patients with bilateral severe to profound sensorineural hearing loss. However, hearing with both ears as a result of bilateral cochlear implantation may offer added benefits.

methodsWe completed a health technology assessment, which included an evaluation of clinical benefits and harms, value for money, budget impact, and patient preferences related to bilateral cochlear implantation. We performed a systematic literature search for studies on bilateral cochlear implantation in adults and children from inception to March 2017. We conducted a cost-utility analysis with a lifetime horizon from a public payer perspective and analyzed the budget impact of publicly funding bilateral cochlear implantation in adults and children in Ontario for the next 5 years. Finally, we conducted interviews with adults who have sensorineural hearing loss and unilateral or bilateral cochlear implants, and with parents of children with bilateral cochlear implants.

resultsWe included 24 publications (10 in adults, 14 in children) in the clinical evidence review. Compared with unilateral cochlear implantation, bilateral cochlear implantation improved sound localization, speech perception in noise, and subjective benefits of hearing in adults and children with severe to profound sensorineural hearing loss (GRADE: moderate to high). Bilateral cochlear implantation also allowed for better language development and more vocalization in preverbal communication in children (GRADE: moderate). The safety profile was acceptable.Bilateral cochlear implantation was more expensive and more effective than unilateral cochlear implantation. The incremental cost-effectiveness ratio was $48,978/QALY in adults and between $27,427/QALY and $30,386/QALY in children. Cost-effectiveness was highly dependent on the quality-of-life values used. We estimated that the net budget impact of publicly funding bilateral cochlear implantation for adults in Ontario would be between $510,000 and $780,000 per year for the next 5 years.Patients described the social and emotional effects of hearing loss, and the benefits and challenges of using cochlear implants.

conclusionsBased on evidence of moderate to high quality, we found that bilateral cochlear implantation improved hearing in adults and children with severe to profound sensorineural hearing loss. Bilateral cochlear implantation was potentially cost-effective compared to unilateral cochlear implantation in adults and children. Patients with sensorineural hearing loss reported the positive effects of cochlear implants, and patients with unilateral cochlear implants generally expressed a desire for bilateral implants.