COPD: Evidence-based medicine or the patient-centered medicine?

摘要

COPD is the most common chronic respiratory disease. Today it is the 4th highest cause of death worldwide and therefore it should always be considered when a patient has chronic dyspnea, cough with or without sputum production, and a history of exposure to risk factors. The diagnosis always requires a spirometry and the ratio FEV1/FVC (or FEV1/VC) is what is normally accepted as the index that defines airway obstruction.1 Airflow limitation that is not fully reversible is defined by the Global Initiative for Obstructive Lung Diseases2 (GOLD) as a post-bronchodilator FEV1/FVC < 0.7, and by the ATS/ERS Task Force position paper3 as a ratio ≤0.7. However, this diagnostic criterion has been increasingly questioned. Although simpler and easier to use in primary care settings worldwide, some authors have claimed that it can miss the diagnosis in younger, predominantly female individuals where an early diagnosis brings the greatest benefit, and can lead to over-diagnosis of COPD in older men, missing a heart disease diagnosis, or even an asthma diagnosis, which require a different approach. So, they argue that the lower limit of normal (LLN) criterion (FEV1/FVC < LLN) should be used instead. Some authors also propose a low FEV1/FVC ratio in any criteria, coupled with a FEV1 <0.8 of the predicted value.4 In fact, there is currently no consensus about the best criteria to be used in COPD. In 2010, 150 international experts and 12 international organizations asked GOLD to change its definition of airflow obstruction to LLN criterion,5 and, in relation to the use of LLN, a recent editorial in the ERJ stresses the need to improve the diagnosis of early COPD.