Fackrell Kathryn, Hall Deborah A, Barry Johanna G, Hoare Derek J
NIHR Nottingham Biomedical Research Centre, Nottingham, UK; Otology and Hearing Group, Division of Clinical Neuroscience, School of Medicine, University of Nottingham, UK.
NIHR Nottingham Biomedical Research Centre, Nottingham, UK; Otology and Hearing Group, Division of Clinical Neuroscience, School of Medicine, University of Nottingham, UK.
Hear Res. 2018 Feb;358:74-85. doi: 10.1016/j.heares.2017.10.016. Epub 2017 Nov 10.
The Tinnitus Functional Index (TFI) has been optimised as a diagnostic tool for quantifying the functional impact of tinnitus in US veteran and civilian groups. However, the TFI has not been fully evaluated for use in other English-speaking clinical populations despite its increasingly popular uptake. Here, a prospective multi-site longitudinal validation study was conducted to evaluate psychometric properties relevant to the UK clinical population. Guided by quality criteria for the measurement properties of health-related questionnaires, we specifically evaluated three diagnostic properties relating to the degree to which the TFI (i) covers the eight dimensions proposed to be important for diagnosis, (ii) reliably distinguishes individual differences in severity of tinnitus, and (iii) reliably measures the functional impact of tinnitus. We also examine whether clinically meaningful interpretations of the scores can be produced for the UK population.
Twelve National Health Service audiology clinics across the UK recruited 255 tinnitus patients to complete questionnaires at four time-intervals, from initial clinical assessment and then over a nine-month period. Patients completed the TFI, the Tinnitus Handicap Inventory (THI), tinnitus case history questions, a Global rating of Perceived Problem with tinnitus and a Clinical Global Impression of perceived change in tinnitus. Baseline TFI data were used to examine the factor structure, construct validity and interpretability of the TFI. Follow-up TFI data were used to examine reliability.
Confirmatory factor analysis suggested that of the eight subscales (factors) initially established for the TFI, the 'Auditory' subscale did not contribute to the overall construct 'functional impact of tinnitus', and a modified seven-factor model (TFI-22) better fit the variance in the patient scores. Both the global 25-item TFI and the global TFI-22 scores showed exceptionally high internal consistency (α ≥ 0.95), high construct validity with the THI (r = 0.80) and high test-retest reliability (ICC = 0.87). Test-retest agreement however was only deemed to be borderline acceptable (89%). Receiver Operator Characteristic analysis indicated the 25-item TFI and TFI-22 has excellent ability to distinguish between different levels of impact (Area under the curve > 0.7).
The TFI was confirmed to cover multiple symptom domains, measuring a multi-domain construct of tinnitus, and satisfies a range of psychometric requirements for a good clinical measure, including having excellent reliability, stability over time and sensitivity to individual differences in tinnitus severity. However, a modified seven-factor structure without the Auditory subscale (TFI-22) is recommended for calculating a global composite score for UK patients. Using patients' experience and Receiver Operator Characteristic analysis, a grading system was presented which identifies the distinct grades of tinnitus impact in the UK clinical population that is broadly comparable to the US-based system.
耳鸣功能指数（TFI）已被优化为一种诊断工具，用于量化耳鸣对美国退伍军人和平民群体的功能影响。然而，尽管TFI的应用越来越广泛，但尚未在其他英语临床人群中进行全面评估。在此，我们开展了一项前瞻性多中心纵向验证研究，以评估与英国临床人群相关的心理测量特性。以健康相关问卷测量特性的质量标准为指导，我们特别评估了与TFI相关的三个诊断特性，即（i）TFI涵盖对诊断重要的八个维度的程度，（ii）可靠地区分耳鸣严重程度的个体差异，以及（iii）可靠地测量耳鸣的功能影响。我们还研究了是否可以为英国人群生成具有临床意义的分数解释。
英国各地的12家国民保健服务听力诊所招募了255名耳鸣患者，在四个时间点完成问卷，从初始临床评估开始，然后在九个月的时间内进行。患者完成了TFI、耳鸣障碍量表（THI）、耳鸣病史问题、耳鸣感知问题的总体评分以及耳鸣感知变化的临床总体印象。基线TFI数据用于检验TFI的因子结构、结构效度和可解释性。随访TFI数据用于检验信度。
验证性因子分析表明，在最初为TFI建立的八个子量表（因子）中，“听觉”子量表对“耳鸣的功能影响”这一总体结构没有贡献，一个修改后的七因子模型（TFI - 22）更适合患者分数的方差。25项总体TFI和总体TFI - 22分数均显示出极高的内部一致性（α≥0.95）、与THI的高结构效度（r = 0.80）和高重测信度（ICC = 0.87）。然而，重测一致性仅被认为勉强可以接受（89%）。受试者工作特征分析表明，25项TFI和TFI - 22具有出色的区分不同影响水平的能力（曲线下面积>0.7）。
TFI被证实涵盖多个症状领域，测量耳鸣的多领域结构，并满足作为一种良好临床测量工具的一系列心理测量要求，包括具有出色的信度、随时间的稳定性以及对耳鸣严重程度个体差异的敏感性。然而，建议使用不包括“听觉”子量表的修改后的七因子结构（TFI - 22）来计算英国患者的总体综合评分。利用患者的经验和受试者工作特征分析，提出了一种分级系统，该系统确定了英国临床人群中与美国系统大致可比的不同等级的耳鸣影响。
