Cough Research Team, Manchester University NHS Foundation Trust, Manchester, UK.
Division of Psychology and Mental Health, The University of Manchester, Manchester, UK.
BMJ Open Respir Res. 2024 Aug 13;11(1):e002430. doi: 10.1136/bmjresp-2024-002430.
Refractory or unexplained chronic cough (RUCC) is a common clinical problem with no effective diagnostic tools. The Sensations and Triggers Provoking Cough questionnaire (TOPIC) was developed to characterise cough in RUCC versus cough in other conditions.
Content analysis of participant interviews discussing the sensations and triggers of chronic cough informed TOPIC development. Participants with chronic cough completed the draft-TOPIC (a subset repeating 5-7 days later), St George's Respiratory Questionnaire (SGRQ), Cough Severity Diary (CSD) and Global Rating of Change Scale. The draft-TOPIC item list was reduced in hierarchical and Rasch analysis to refine the questionnaire to the TOPIC.
49 items describing the triggers and sensations of cough were generated from participant interviews (RUCC n=14, chronic obstructive pulmonary disease (COPD) n=11, interstitial lung disease (ILD) n=10, asthma n=11, bronchiectasis n=3, cystic fibrosis n=7). 140 participants (median age 60.0 (19.0-88.0), female 56.4%; RUCC n=39, ILD n=38, asthma n=45, COPD n=6, bronchiectasis n=12) completed draft-TOPIC, where items with poor 'fit' for RUCC were removed to create TOPIC (8 trigger items, 7 sensation items). Median TOPIC score was significantly higher in RUCC (37.0) vs ILD (24.5, p=0.009) and asthma (7.0, p<0.001), but not bronchiectasis (20.0, p=0.318) or COPD (18.5, p=0.238), likely due to small sample sizes. The Rasch model demonstrated excellent fit in RUCC (χ=22.04, p=0.85; PSI=0.88); as expected. When all participant groups were included, fit was no longer demonstrated (χ=66.43, p=0.0001, PSI=0.89) due to the increased heterogeneity (CI=0.077). TOPIC correlated positively with SGRQ (r=0.47, p<0.001) and CSD (r=0.63, p<0.001). The test-retest reliability of TOPIC (intraclass correlation coefficient) was excellent (r=0.90, p<0.001).
High TOPIC scores in the RUCC patients suggest their cough is characterised by specific sensations and triggers. Validation of TOPIC in cough clinics may demonstrate value as an aid to identify features of RUCC versus cough in other conditions.
难治性或不明原因的慢性咳嗽（RUCC）是一种常见的临床问题，目前尚无有效的诊断工具。感官和触发因素引发咳嗽问卷（TOPIC）是为了描述 RUCC 与其他疾病的咳嗽特征而开发的。
对讨论慢性咳嗽感觉和触发因素的参与者访谈进行内容分析，为 TOPIC 的开发提供信息。慢性咳嗽患者完成了草稿-TOPIC（其中一部分在 5-7 天后重复）、圣乔治呼吸问卷（SGRQ）、咳嗽严重程度日记（CSD）和全球变化量表。通过层次分析和 Rasch 分析减少草稿-TOPIC 的项目列表，以完善问卷。
从参与者访谈中生成了 49 个描述咳嗽触发因素和感觉的项目（RUCC n=14、慢性阻塞性肺疾病（COPD）n=11、间质性肺疾病（ILD）n=10、哮喘 n=11、支气管扩张 n=3、囊性纤维化 n=7）。140 名参与者（中位数年龄 60.0（19.0-88.0），女性 56.4%；RUCC n=39、ILD n=38、哮喘 n=45、COPD n=6、支气管扩张 n=12）完成了草稿-TOPIC，其中 RUCC 项目的“拟合”较差的项目被删除，以创建 TOPIC（8 个触发项目，7 个感觉项目）。RUCC 的 TOPIC 评分中位数明显高于 ILD（24.5，p=0.009）和哮喘（7.0，p<0.001），但与支气管扩张（20.0，p=0.318）或 COPD（18.5，p=0.238）无差异，可能是由于样本量小。Rasch 模型显示 RUCC 拟合度良好（χ=22.04，p=0.85；PSI=0.88）；如预期的那样。当包括所有参与者群体时，由于异质性增加（CI=0.077），拟合不再得到证实（χ=66.43，p=0.0001，PSI=0.89）。TOPIC 与 SGRQ（r=0.47，p<0.001）和 CSD（r=0.63，p<0.001）呈正相关。TOPIC 的测试-重测信度（组内相关系数）非常好（r=0.90，p<0.001）。
RUCC 患者的高 TOPIC 评分表明他们的咳嗽具有特定的感觉和触发因素。在咳嗽诊所验证 TOPIC 可能有助于识别 RUCC 与其他疾病的咳嗽特征。
