Haggard M, Gatehouse S
MRC Institute of Hearing Research, University Park, Nottingham, UK.
Br J Audiol. 1993 Oct;27(5):303-18. doi: 10.3109/03005369309076709.
A definition of hearing aid candidature is required for planning and other purposes. The number of candidates in the population actually receiving an adequate fitting would provide the major index of whether audiology services achieve their major public health goal. Many diverse factors determine the benefit that an individual receives from a hearing aid, and hence could in principle be included in some composite criterion for appropriate candidature reflecting the cost-effectiveness of patterns of provision. However, the complexity of universal capture, on those fitted with hearing aids, of data giving full auditory and demographic characteristics is beyond current routine NHS information systems. The most powerful known determinant established to date both of auditory disability and benefit is average hearing threshold level (HTL). Hearing threshold levels are hence both a necessary part of the fitting process and, given the data from the National Study of Hearing, a sufficient basis for computing population prevalences of hearing characteristics and service uptake in the major demographic strata. We report epidemiological data on consultation about problems with ears or hearing and uptake of hearing aids, which lead us to recommend a two-part candidature criterion on hearing threshold levels (0.5-4.0 kHz average): EITHER (a) better ear HTL > or = 35 dB OR (b) (15 dB < or = better ear HTL < 35 dB) WHEN worse ear HTL > or = 45 dB. The asymmetric component (b) may appear contentious, but is directly supported both by the epidemiological data and by further clinical data on benefit measured as performance on speech-in-noise tests. The proposed criterion is not over-liberal in clinical or related technological terms, but against the high prevalence of impairments in the population, the current provision and uptake of hearing aids in the UK still appear modest (about 3.3% in the population, and just under one-third of those qualifying by our criterion). Whatever the means of providing hearing aids, authorities charged with meeting the needs of their populations require such statistical indicators to know whether service delivery is appropriately geared. They should not use such an indicator as a basis of entitlement, as there are certainly individuals outside the criterion who receive benefit from their hearing aids. Equally, technological progress could expand the boundaries of candidature.
为了规划及其他目的，需要对助听器候选资格进行定义。实际获得合适助听器佩戴的人群数量将成为衡量听力学服务是否实现其主要公共卫生目标的主要指标。许多不同因素决定了个体从助听器中获得的益处，因此原则上可以纳入某种综合标准，以确定合适的候选资格，反映服务提供模式的成本效益。然而，要全面获取佩戴助听器者的完整听觉和人口统计学特征数据，其复杂性超出了目前英国国家医疗服务体系（NHS）的常规信息系统能力范围。迄今为止，已知的对听觉残疾和益处影响最显著的因素是平均听力阈值水平（HTL）。因此，听力阈值水平既是验配过程的必要组成部分，又鉴于全国听力研究的数据，是计算主要人口阶层听力特征的人群患病率及服务使用率的充分依据。我们报告了关于耳部或听力问题咨询以及助听器使用情况的流行病学数据，据此建议采用基于听力阈值水平（0.5 - 4.0千赫兹平均水平）的两部分候选资格标准：要么（a）较好耳的HTL≥35分贝，要么（b）（15分贝≤较好耳的HTL＜35分贝）且较差耳的HTL≥45分贝。不对称部分（b）可能看似有争议，但得到了流行病学数据以及关于以噪声环境下言语测试表现衡量的益处的进一步临床数据的直接支持。从临床或相关技术角度来看，所提议的标准并非过于宽松，但鉴于人群中听力损伤的高患病率，英国目前助听器的供应和使用情况仍然较为有限（约占人口的3.3%，且仅略低于符合我们标准人数的三分之一）。无论提供助听器的方式如何，负责满足民众需求的当局需要此类统计指标，以了解服务提供是否恰当。他们不应将此类指标作为资格认定的依据，因为肯定有不符合该标准的个体也从助听器中受益。同样，技术进步可能会扩大候选资格的范围。
