Background

Cough is one of the most common symptoms in general and pulmonary medicine with profound negative impact on health-related quality of life (HRQL). The Leicester Cough Questionnaire (LCQ) is a validated HRQL questionnaire, yet a validated German version of the LCQ is not available and it has never been tested in a cohort with sarcoidosis.

Objectives

To translate the LCQ into German and determine its psychometric properties.

Methods

The LCQ was translated in a forward-backward approach. Structured interviews in sarcoidosis patients were performed. Subsequently, sarcoidosis patients were asked to answer the German LCQ and comparative questionnaires. Distribution properties, item difficulty, concurrent validity, Rasch model fit and internal consistency of the German LCQ were determined.

Results

200 patients with sarcoidosis were included. We provide evidence for reliability, unidimensionality and internal consistency. However, only a moderate correlation with general and respiratory-specific HRQL questionnaires, no Rasch model fit could be shown. Skewed responses caused by floor effects were detected.

Conclusion

We demonstrate that the German LCQ is valid and reliable and its psychometric properties fulfil the standards required for its use in clinical settings as well as in interventional trials.

中文翻译：

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德文版结节病患者莱斯特咳嗽问卷的心理计量学特征

背景

咳嗽是普通和肺部医学中最常见的症状之一，对健康相关的生活质量（HRQL）产生深远的负面影响。莱斯特咳嗽问卷（LCQ）是经过验证的HRQL问卷，但是尚无经过验证的德语版LCQ，也从未在结节病患者队列中进行过测试。

目标

将LCQ翻译成德语并确定其心理计量特性。

方法

立法会质询以向前-向后的方式翻译。对结节病患者进行了结构化访谈。随后，结节病患者被要求回答德国LCQ和比较问卷。确定了分布特性，项目难度，并发有效性，Rasch模型拟合和德国LCQ的内部一致性。

结果

包括200例结节病患者。我们提供可靠性，一维性和内部一致性的证据。但是，仅与一般和针对呼吸的HRQL问卷具有中等相关性，无法显示Rasch模型拟合。检测到由地板效应引起的偏斜响应。

结论

我们证明了德国LCQ是有效和可靠的，并且其心理测量特性符合其在临床环境和干预性试验中使用所需的标准。