Mittal Richa, Chhabra Sunil K
a Department of Pulmonary Medicine , Vallabhbhai Patel Chest Institute, University of Delhi , Delhi , India.
COPD. 2017 Feb;14(1):1-6. doi: 10.1080/15412555.2016.1230844. Epub 2016 Oct 10.
The new A-B-C-D Global Initiative for Chronic Obstructive Lung Disease (GOLD) classification of severity of chronic obstructive pulmonary disease (COPD) is based on combined symptoms and exacerbation risk assessment. The assumed equivalence between dyspnoea modified Medical Research Council (mMRC) grade ≥2 and COPD Assessment Test (CAT) score ≥ 10 to identify more symptoms has been questioned. Whether the exacerbation risk assessment criteria, old GOLD spirometry staging and frequency of exacerbations, are equivalent has not been examined. We evaluated the extent of agreement between these alternative criteria and whether it improved by redefining the equivalence between mMRC grade and CAT score. CAT scores, mMRC grades of dyspnoea, frequency of exacerbations and spirometry stages were computed in 400 patients with COPD. Receiver operating characteristic curve was analysed to determine the best CAT score to identify more symptoms. CAT scores across mMRC grades and the frequency of exacerbations across spirometry stages showed substantial overlaps. The symptoms criteria gave discordant classification in 88 (22%) patients (kappa 0.62) and the exacerbation risk assessment criteria in 181 (45%) patients (kappa 0.12). A CAT score of ≥10 had 82% sensitivity but 24% specificity to identify mMRC grade ≥ 2, while a score of 17 had 98% specificity but a low sensitivity of 52% and did not improve the agreement. We conclude that symptoms and exacerbation risk assessment criteria of the new GOLD classification yield discordant group categorisations. Lack of any satisfactory equivalence between CAT score and mMRC grades implies that the former cannot be used alone. Using the higher of mMRC ≥ 2 and CAT score ≥ 17 to identify more symptoms would avoid discordant categorisation.
慢性阻塞性肺疾病（COPD）全球倡议（GOLD）新的A - B - C - D慢性阻塞性肺疾病严重程度分类基于症状和急性加重风险评估相结合。呼吸困难改良医学研究委员会（mMRC）分级≥2与慢性阻塞性肺疾病评估测试（CAT）评分≥10之间用于识别更多症状的假定等效性受到了质疑。急性加重风险评估标准、旧的GOLD肺功能分级和急性加重频率是否等效尚未得到检验。我们评估了这些替代标准之间的一致程度，以及重新定义mMRC分级和CAT评分之间的等效性是否能改善这种一致程度。对400例慢性阻塞性肺疾病患者计算了CAT评分、呼吸困难的mMRC分级、急性加重频率和肺功能分级。分析受试者工作特征曲线以确定识别更多症状的最佳CAT评分。不同mMRC分级的CAT评分以及不同肺功能分级的急性加重频率显示出大量重叠。症状标准在88例（22%）患者中给出了不一致的分类（kappa值为0.62），急性加重风险评估标准在181例（45%）患者中给出了不一致的分类（kappa值为0.12）。CAT评分≥10识别mMRC分级≥2的敏感性为82%，但特异性为24%，而评分≥17时特异性为98%，但敏感性低至52%，且并未改善一致性。我们得出结论，新GOLD分类的症状和急性加重风险评估标准产生了不一致的分组分类。CAT评分与mMRC分级之间缺乏任何令人满意的等效性意味着前者不能单独使用。使用较高的mMRC≥2和CAT评分≥17来识别更多症状可避免不一致的分类。
