Unilateral versus simultaneous bilateral cochlear implantation in adults : a randomized controlled trial

Worldwide, more than 550 million people suffer from disabling hearing loss (≥35dB in the better ear). More than 60 million suffer from severe hearing loss or worse (≥61dB). The most common type of hearing loss is sensorineural hearing loss, caused by a defect inside the cochlea. Hearing aids are usually the first treatment option. In case of a severe hearing impairment, hearing aids may be inadequate and cochlear implants may be considered. A cochlear implant is a device that can receive sound, process, transmit and convert it into electrical signals, and present it to the brain by direct stimulation of the auditory nerve. This is possible thanks to an electrode array that is surgically inserted into the cochlea. Cochlear implantation (CI) has proven to be very successful. It enables deaf people to hear again. In the Netherlands, adult patients eligible for CI, normally receive reimbursement for one cochlear implant only. Cochlear implantees are, overall, deaf in both ears and after receiving a cochlear implant, they still have a significant hearing impairment. It is well known that people with only one functioning ear find it difficult to understand speech in noise and to determine which direction sounds come from. Several studies have shown that bilateral CI (BiCI) may be beneficial in these difficult listening situations. However, Zorginstituut Nederland (ZiNL), decided that the quality of these studies, investigating the benefits of BiCI compared with unilateral CI (UCI), is too low to justify reimbursement of BiCI in adults. In order to properly investigate the benefits and cost-utility of BiCI compared with UCI in adults with a severe postlingual hearing loss, we started a multicenter, randomized controlled trial in 2010. Thirty-eight patients were included in this study. Nineteen patients received two cochlear implants simultaneously. The other 19 first received one cochlear implant and a second implant 2 years later. To adequately test the participants’ spatial listening capabilities, we used the Dutch version of the AB-York crescent of sound. The primary outcome measure of our study was speech understanding in noise, with speech and noise coming from straight ahead, measured with the U-STARR (Utrecht Sentence Test At Randomized Roving levels). This test is explained and validated in this thesis. The main outcomes of our research are: 1. That simultaneous BiCI compared with UCI is effective, and 2. That BiCI is cost-effective compared with the Dutch generally accepted willingness to pay. We also performed a review study to analyze what the effect of time between sequential implantations is on hearing performance. We show that a second implant can be beneficial even with a substantial interval between implantations, although the quality of the evidence was rather poor

The Cost-utility of bilateral cochlear implantation: A Systematic Review.

OBJECTIVES/HYPOTHESIS: The (cost-)effectiveness and the subsequent reimbursement of bilateral cochlear implantation has been vigorously debated. Throughout the world healthcare commissioners are still struggling with the decision to reimburse bilateral implantation. Given this debate, this study's objective was to review the literature on the cost-utility of bilateral cochlear implantation in both children and adults, and study the impact of the used cost and quality-of-life estimates. STUDY DESIGN: Systematic review. METHODS: Electronic databases were systematically searched for relevant studies published up to December 2010. All studies reporting on cost-utility and bilateral cochlear implantation were included. RESULTS: Five studies fulfilled the inclusion criteria. The methodological quality of the studies, assessed with Drummond's checklist of cost-effectiveness studies, varied from poor to good. The assumptions regarding gain in quality-adjusted life years (QALYs) and direct costs varied among studies, resulting in a varying gain in QALY (0.38-1.93). The incremental cost-effectiveness ratios for bilateral cochlear implantation differed widely across studies for both children and adults (children: $30,973-$94,340; adults: $38,189-$132,160) and were inversely related to the gain in QALY, cost reductions due to simultaneous implantation, and discounts offered on the second implant. CONCLUSIONS: The incremental cost-effectiveness ratios for bilateral cochlear implantation vary widely and appear to depend on the gain in QALY due to the second implant. The results of this review confirm that more empirical data are required to estimate the cost-effectiveness of bilateral implantation. Laryngoscope, 121:2604-2609, 2011

What is the effect of time between sequential cochlear implantations on hearing in adults and children? A systematic review of the literature.

Item does not contain fulltextOBJECTIVES/HYPOTHESIS: Bilateral cochlear implantation is a safe and effective intervention for severe sensorineural hearing loss and is believed to be more effective than unilateral implantation. This review article investigates the effect of time between sequential cochlear implantations on hearing results in both adults and children. STUDY DESIGN: Systematic review of cohort studies. METHODS: We searched PubMed, Embase, and CINAHL from inception to August 16, 2010, using the terms hearing loss, cochlear implant, delay, and their synonyms. RESULTS: Eleven studies evaluating the effect of time between sequential cochlear implantations on hearing performance were included. Although the quality of studies was poor because of a significant risk of bias, all studies reported that auditory performance is better in a bilateral listening situation than with either one cochlear implant activated unilaterally. Five studies discussed postlingually deafened adults. In four, bilateral hearing was not affected by the amount of time between implantations. One study did report a negative effect of delay on speech intelligibility in silence. Seven studies discussed prelingually deafened children. None reported a negative effect of interimplantation delay on sound localization performance. One study reported poorer results after extended intervals on speech intelligibility in silence and two in noise. CONCLUSIONS: Current evidence suggests that a second implant can be beneficial even after a substantial interval between sequential implantations. The quality of the evidence is, however, rather poor; to confirm this postulation, high-quality trials assessing the effectiveness of a second cochlear implant after a time delay should be initiated.1 september 201

Tinnitus after Simultaneous and Sequential Bilateral Cochlear Implantation

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No Difference in Behavioral and Self-Reported Outcomes for Simultaneous and Sequential Bilateral Cochlear Implantation: Evidence From a Multicenter Randomized Controlled Trial

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Development of a Squelch Effect in Adult Patients After Simultaneous Bilateral Cochlear Implantation

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Cost-Utility of Bilateral Versus Unilateral Cochlear Implantation in Adults: A Randomized Controlled Trial

OBJECTIVE: To study the cost-utility of simultaneous bilateral cochlear implantation (CI) versus unilateral CI. STUDY DESIGN: Randomized controlled trial (RCT). SETTING: Five tertiary referral centers. PATIENTS: Thirty-eight postlingually deafened adults eligible for cochlear implantation. INTERVENTIONS: A cost-utility analysis was performed from a health insurance perspective. MAIN OUTCOME MEASURES: Utility was assessed using the HUI3, TTO, VAS on hearing, VAS on general health and EQ-5D. We modeled the incremental cost per quality-adjusted life year (QALY) of unilateral versus bilateral CI over periods of 2, 5, 10, 25 years, and actual life-expectancy. RESULTS: Direct costs for unilateral and bilateral CI were euro43,883 +/- euro11,513(SD) and euro87,765 +/- euro23,027(SD) respectively. Annual costs from the second year onward were euro3,435 +/- euro1,085(SD) and euro6,871 +/- euro2,169(SD), respectively. A cost-utility analysis revealed that a second implant became cost-effective after a 5- to 10-year period, based on the HUI3, TTO, and VAS on hearing. CONCLUSION: This is the first study that describes a cost-utility analysis to compare unilateral with simultaneous bilateral CI in postlingually deafened adults, using a multicenter RCT. Compared with accepted societal willingness-to-pay thresholds, simultaneous bilateral CI is a cost-effective treatment for patients with a life expectancy of 5-10 years or longer

Objective and Subjective Measures of Simultaneous vs Sequential Bilateral Cochlear Implants in Adults: A Randomized Clinical Trial

Item does not contain fulltextImportance: To date, no randomized clinical trial on the comparison between simultaneous and sequential bilateral cochlear implants (BiCIs) has been performed. Objective: To investigate the hearing capabilities and the self-reported benefits of simultaneous BiCIs compared with those of sequential BiCIs. Design, Setting, and Participants: A multicenter randomized clinical trial was conducted between January 12, 2010, and September 2, 2012, at 5 tertiary referral centers among 40 participants eligible for BiCIs. Main inclusion criteria were postlingual severe to profound hearing loss, age 18 to 70 years, and a maximum duration of 10 years without hearing aid use in both ears. Data analysis was conducted from May 24 to June 12, 2016. Interventions: The simultaneous BiCI group received 2 cochlear implants during 1 surgical procedure. The sequential BiCI group received 2 cochlear implants with an interval of 2 years between implants. Main Outcomes and Measures: First, the results 1 year after receiving simultaneous BiCIs were compared with the results 1 year after receiving sequential BiCIs. Second, the results of 3 years of follow-up for both groups were compared separately. The primary outcome measure was speech intelligibility in noise from straight ahead. Secondary outcome measures were speech intelligibility in noise from spatially separated sources, speech intelligibility in silence, localization capabilities, and self-reported benefits assessed with various hearing and quality of life questionnaires. Results: Nineteen participants were randomized to receive simultaneous BiCIs (11 women and 8 men; median age, 52 years [interquartile range, 36-63 years]), and another 19 participants were randomized to undergo sequential BiCIs (8 women and 11 men; median age, 54 years [interquartile range, 43-64 years]). Three patients did not receive a second cochlear implant and were unavailable for follow-up. Comparable results were found 1 year after simultaneous or sequential BiCIs for speech intelligibility in noise from straight ahead (difference, 0.9 dB [95% CI, -3.1 to 4.4 dB]) and all secondary outcome measures except for localization with a 30 degrees angle between loudspeakers (difference, -10% [95% CI, -20.1% to 0.0%]). In the sequential BiCI group, all participants performed significantly better after the BiCIs on speech intelligibility in noise from spatially separated sources and on all localization tests, which was consistent with most of the participants' self-reported hearing capabilities. Speech intelligibility-in-noise results improved in the simultaneous BiCI group up to 3 years following the BiCIs. Conclusions and Relevance: This study shows comparable objective and subjective hearing results 1 year after receiving simultaneous BiCIs and sequential BiCIs with an interval of 2 years between implants. It also shows a significant benefit of sequential BiCIs over a unilateral cochlear implant. Until 3 years after receiving simultaneous BiCIs, speech intelligibility in noise significantly improved compared with previous years. Trial Registration: trialregister.nl Identifier: NTR1722

Effect of unilateral and simultaneous bilateral cochlear implantation on tinnitus: A Prospective Study

OBJECTIVES/HYPOTHESIS: To determine the effect of cochlear implantation on tinnitus perception in patients with severe bilateral postlingual sensorineural hearing loss and to demonstrate possible differences between unilateral and bilateral cochlear implantation. STUDY DESIGN: Prospective study. METHODS: Thirty-eight adult patients were included in this prospective study, as part of a multicenter randomized controlled trial investigating the benefits of bilateral cochlear implantation versus unilateral cochlear implantation. Pre- and postoperative tinnitus perception scores were evaluated, before and 1 year after implantation on three tinnitus questionnaires; the Tinnitus Handicap Inventory (THI), the Tinnitus Questionnaire (TQ), and a visual analogue scale for tinnitus burden. RESULTS: Before implantation, the tinnitus prevalence was 42.1% (16 of 38) in the whole study group. One year after implantation, the tinnitus questionnaire scores had decreased in 71.4% according to the TQ and 80.0% according to the THI. Tinnitus was induced after cochlear implantation in six patients, five in the bilateral and one in the unilateral group. CONCLUSIONS: Our study shows that cochlear implantation is effective in the reduction of tinnitus in patients with bilateral sensorineural hearing loss who suffered from preoperative tinnitus. Conversely, tinnitus may also increase or even be induced by the cochlear implantation itself. Cochlear implant candidates should be well informed about these possible consequences before undergoing surgery. LEVEL OF EVIDENCE: 2b Laryngoscope, 126:956-961, 2016

Comparison of Bilateral and Unilateral Cochlear Implantation in Adults A Randomized Clinical Trial

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