Lovett Rosemary Elizabeth Susan, Vickers Deborah Anne, Summerfield Arthur Quentin
1Ear Institute, University College London, London, United Kingdom; and 2Department of Psychology and Hull York Medical School, University of York, York, United Kingdom.
Ear Hear. 2015 Jan;36(1):14-23. doi: 10.1097/AUD.0000000000000087.
Policy-makers have struggled to define the minimum degree of hearing impairment at which children should be offered cochlear implants rather than the less invasive alternative of acoustic hearing aids. This study compared outcomes for children with bilateral cochlear implants and children with bilateral hearing aids, to determine a criterion of candidacy for pediatric bilateral cochlear implantation.
This observational study measured the listening skills of children who received routine audiological care in the United Kingdom. Participants were recruited from hospitals, educational services, and charities. Eligibility criteria included a diagnosis of hearing impairment before 31 months of age and pure-tone thresholds greater than or equal to 50 dB HL at 2 and 4 kHz bilaterally. Seventy-one children participated, aged 46 to 86 months (mean 64 months). Twenty-eight children used bilateral implants provided in a simultaneous surgery; 43 used bilateral digital hearing aids. The two groups of children were demographically similar in variables that predict outcomes for children with hearing impairment. Children's ability to understand speech was measured using closed-set tests of word discrimination in three conditions: in quiet, in pink noise, and in two-talker babble. For each listening test, an actuarial method was used to compare the distribution of scores from children with cochlear implants and children with hearing aids. The aim was to calculate the unaided pure-tone average (PTA) hearing level at which a child has odds of 4:1 of a better outcome with implants than with hearing aids. The PTA associated with odds of 4:1 has been used previously to define criteria of candidacy for implantation. The main analyses used a four-frequency PTA (mean of unaided thresholds at 0.5, 1, 2, and 4 kHz in the better-hearing ear). Additional analyses used a three-frequency PTA (0.5, 1, and 2 kHz) and two-frequency PTA (2 and 4 kHz).
Odds of 4:1 of a better outcome with implants were associated with a four-frequency PTA of 79, 86, and 76 dB HL for tests of word discrimination in quiet, noise, and babble, respectively. The mean of these three estimates is 80 dB HL. It can be difficult to measure a four-frequency PTA in young children, but a two-frequency PTA typically can be measured. Odds of 4:1 were associated with a two-frequency PTA of 83, 92, and 80 dB HL for tests of word discrimination in quiet, noise, and babble, respectively. The mean of these three estimates is 85 dB HL.
Children with an unaided four-frequency PTA of 80 dB HL or poorer in both ears should be considered candidates for bilateral cochlear implantation. In cases where a four-frequency PTA cannot be measured, the criterion of candidacy should be a two-frequency PTA of 85 dB HL or poorer in both ears. If adopted by policy-makers, these recommendations would expand the provision of cochlear implants among children in England and Wales.
政策制定者一直在努力界定儿童应接受人工耳蜗植入而非侵入性较小的声学助听器这一替代方案时的最低听力损伤程度。本研究比较了双侧人工耳蜗植入儿童和双侧使用助听器儿童的治疗效果,以确定小儿双侧人工耳蜗植入的候选标准。
这项观察性研究对在英国接受常规听力学护理的儿童的听力技能进行了测量。参与者从医院、教育服务机构和慈善机构招募。入选标准包括在31个月龄前被诊断为听力损伤,且双侧2kHz和4kHz处的纯音听阈大于或等于50dB HL。71名儿童参与研究,年龄在46至86个月(平均64个月)。28名儿童在同期手术中使用双侧植入物;43名儿童使用双侧数字助听器。两组儿童在预测听力损伤儿童治疗效果的变量方面在人口统计学上相似。使用在三种情况下进行的单词识别封闭测试来测量儿童理解言语的能力:安静环境、粉红噪声环境和双说话者嘈杂环境。对于每次听力测试,采用精算方法比较人工耳蜗植入儿童和使用助听器儿童的得分分布。目的是计算在植入物治疗效果比使用助听器好4:1几率时儿童的无助听纯音平均(PTA)听力水平。先前已使用与4:1几率相关的PTA来定义植入候选标准。主要分析使用四频率PTA(较好耳0.5、1、2和4kHz处无助听阈值的平均值)。额外分析使用三频率PTA(0.5、1和2kHz)和双频率PTA(2和4kHz)。
对于安静、噪声和嘈杂环境中的单词识别测试,植入物治疗效果好4:1的几率分别与四频率PTA为79、86和76dB HL相关。这三个估计值的平均值为80dB HL。在幼儿中测量四频率PTA可能很困难,但通常可以测量双频率PTA。对于安静、噪声和嘈杂环境中的单词识别测试,4:1的几率分别与双频率PTA为83、92和80dB HL相关。这三个估计值的平均值为85dB HL。
双耳无助听四频率PTA为80dB HL或更差的儿童应被视为双侧人工耳蜗植入的候选者。在无法测量四频率PTA的情况下,候选标准应为双耳双频率PTA为85dB HL或更差。如果政策制定者采纳这些建议,将扩大英格兰和威尔士儿童人工耳蜗植入的覆盖面。