Interpreting the Tinnitus Questionnaire (German version): what individual differences are clinically important?

<i>Objective</i>: Reporting of clinical significance is recommended because findings can be statistically significant without being relevant to patients. For aiding clinical interpretation of the Tinnitus Questionnaire (TQ), many investigators use a 5-point change cut-off as a minimal clinically important difference (MCID). But there are shortcomings in how this value was originally determined. <i>Design</i>: The MCID was evaluated by analysing retrospective clinical data on the TQ (German version). Following recommended standards, multiple estimates were computed using anchor- and distribution-based statistical methods. These took into account not only patients’ experience of clinical improvement, but also measurement reliability. <i>Study sample</i>: Pre- and post-intervention scores were assessed for 202 patients. <i>Results</i>: Our six estimates ranged from 5 to 21 points in TQ change score from pre- to post- intervention. The 5-point TQ change score was obtained using a method that considered change between groups, and did not account for measurement error or bias. The size of the measurement error was considerable, and this comprises interpretation of individual patient change scores. <i>Conclusions</i>: To enhance confidence that a TQ change over time in individual patients is clinically meaningful, we advise at least the median MCID of 12 points.

【研究目标】报告临床意义具有必要性，因为研究结果虽可具备统计学显著性，却未必与患者的实际临床需求相关。为辅助耳鸣问卷（Tinnitus Questionnaire, TQ）的临床解读，诸多研究者将5分变化界值作为最小临床重要差异（Minimally Clinically Important Difference, MCID），但该界值的原始确定方式存在一定缺陷。【研究设计】本研究通过分析德语版耳鸣问卷（TQ）的回顾性临床数据，对最小临床重要差异（MCID）进行评估。按照推荐的研究标准，采用基于锚点法与分布法的多种统计方法计算得到多项估计值，这些方法既纳入了患者对临床改善的主观体验，同时也考量了测量信度。【研究样本】本研究共纳入202例患者，对其干预前后的TQ评分进行了评估。【研究结果】本研究得到的6项估计值对应的干预前后TQ变化分区间为5至21分。其中5分的TQ变化界值通过组间差异分析法得出，未考虑测量误差与偏倚。本次研究中测量误差幅度较大，这将对个体患者的变化评分解读产生影响。【研究结论】为提升对个体患者随时间推移的TQ评分变化具有临床意义的判断置信度，我们建议至少采用12分的MCID中位数作为界值。