Dept of Pneumology, Hospital Universitari Vall d'Hebron, Barcelona, Spain.
CIBER de Enfermedades Respiratorias (CIBERES), Barcelona, Spain.
Eur Respir J. 2018 Sep 15;52(3). doi: 10.1183/13993003.00079-2018. Print 2018 Sep.
The vicious circle of dyspnoea-inactivity has been proposed, but never validated empirically, to explain the clinical course of chronic obstructive pulmonary disease (COPD). We aimed to develop and validate externally a comprehensive vicious circle model.We utilised two methods. 1) Identification and validation of all published vicious circle models by a systematic literature search and fitting structural equation models to longitudinal data from the Spanish PAC-COPD (Phenotype and Course of COPD) cohort (n=210, mean age 68 years, mean forced expiratory volume in 1 s (FEV) 54% predicted), testing both the hypothesised relationships between variables in the model ("paths") and model fit. 2) Development of a new model and external validation using longitudinal data from the Swiss and Dutch ICE COLD ERIC (International Collaborative Effort on Chronic Obstructive Lung Disease: Exacerbation Risk Index Cohorts) cohort (n=226, mean age 66 years, mean FEV 57% predicted).We identified nine vicious circle models for which structural equation models confirmed most hypothesised paths but showed inappropriate fit. In the new model, airflow limitation, hyperinflation, dyspnoea, physical activity, exercise capacity and COPD exacerbations remained related to other variables and model fit was appropriate. Fitting it to ICE COLD ERIC, all paths were replicated and model fit was appropriate.Previously published vicious circle models do not fully explain the vicious circle concept. We developed and externally validated a new comprehensive model that gives a more relevant role to exercise capacity and COPD exacerbations.
呼吸困难-不活动的恶性循环已经被提出，但从未经过实证验证，以解释慢性阻塞性肺疾病（COPD）的临床过程。我们旨在开发和验证一个全面的恶性循环模型。我们使用了两种方法。1）通过系统文献检索确定和验证所有已发表的恶性循环模型，并将结构方程模型拟合到来自西班牙 PAC-COPD（COPD 表型和病程）队列的纵向数据（n=210，平均年龄 68 岁，平均用力呼气量在 1 秒内（FEV）为预测值的 54%），检验模型中变量之间假设的关系（“路径”）和模型拟合度。2）使用来自瑞士和荷兰 ICE COLD ERIC（慢性阻塞性肺疾病国际合作研究：加重风险指数队列）队列的纵向数据开发新模型并进行外部验证（n=226，平均年龄 66 岁，平均 FEV 预测值的 57%）。我们确定了九个恶性循环模型，结构方程模型证实了大多数假设的路径，但显示出不合适的拟合度。在新模型中，气流受限、过度充气、呼吸困难、体力活动、运动能力和 COPD 加重仍然与其他变量相关，并且模型拟合度合适。将其拟合到 ICE COLD ERIC 中，所有路径都得到了复制，模型拟合度也合适。以前发表的恶性循环模型并没有完全解释恶性循环的概念。我们开发并验证了一个新的综合模型，该模型赋予了运动能力和 COPD 加重更相关的作用。
