A new approach to grading and treating COPD based on clinical phenotypes
Many previous studies have attempted to identify and quantify the prevalence of different phenotypes of COPD using populations of various sources, severities, and particularities.9 Yet there is no consensus on the number and definition of different phenotypes, from two to 210 million (the estimated number of patientsworldwide).
However, there must be a compromise between the oversimplification of the term COPD as a definition that encompasses the entire spectrum of patients with incompletely reversible airflow obstruction caused largely by smoking and the complexity of considering each patient individually as an orphan disease.
10 This intermediate step might arise by the identification and description of some phenotypes, not only in the biological or epidemiological sense but also from the prognostic and therapeutic point of view, especially at the individual patient level.
After a lengthy but fruitful panel discussion, it was proposed that four different phenotypes of prognostic and therapeutic relevance characterised by the combination of the classical types of emphysema, chronic bronchitis, exacerbators and patients with overlap COPD-asthma be defined.11 The proposed phenotypes are:
(A) infrequent exacerbators with either chronic bronchitis or emphysema;
(B) overlap COPD-asthma;
(C) frequent exacerbators with emphysema predominant; and
(D) frequent exacerbators with chronic bronchitis predominant .
We describe the rationale behind each of these four phenotypes, and their proposed treatment.
