title: Development of a decision tree to assess the severity and prognosis of stable COPD.
abstract: The aim of this study was to develop and validate a new method: a classification and regression tree (CART) based on easily accessible measures to predict mortality in patients with stable chronic obstructive pulmonary disease (COPD). This was a prospective study of two independent prospective cohorts: a derivation cohort with 611 recruited patients and a validation cohort with 348 patients, all followed for 5 yrs. CART analysis was used to predict 5-yr mortality risk using the following covariates from the derivation cohort: age, % predicted forced expiratory volume in 1 s (FEV(1)), dyspnoea, physical activity, general health and number of hospital admissions for COPD exacerbations in the previous 2 yrs. Age (≥ 75 or <75 yrs) provided the first branch of the COPD-CART. The highest mortality risk (0.74) was seen in patients >75 yrs of age with higher levels of dyspnoea and FEV(1) <50% pred. Patients with the lowest risk of 5-yr mortality (0.04) were <55 yrs of age with FEV(1) >35% pred and one or no recent hospitalisations for COPD exacerbations. A simple decision tree that uses variables commonly gathered by physicians can provide a quick assessment of the severity of the disease, as measured by the risk of 5-yr mortality.
authors.affiliation: Service of Pneumology, Hospital de Galdakao-Usansolo, Barrio Labeaga s/n.48960 Galdakao, Bizkaia, Spain. cristobal_esteban@yahoo.es
authors.forename: C
authors.initials: C
authors.lastname: Esteban
authors.forename: I
authors.initials: I
authors.lastname: Arostegui
authors.forename: J
authors.initials: J
authors.lastname: Moraza
authors.forename: M
authors.initials: M
authors.lastname: Aburto
authors.forename: J M
authors.initials: JM
authors.lastname: Quintana
authors.forename: J
authors.initials: J
authors.lastname: Pérez-Izquierdo
authors.forename: S
authors.initials: S
authors.lastname: Aizpiri
authors.forename: A
authors.initials: A
authors.lastname: Capelastegui
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D003663:Decision Trees; D018450:Disease Progression; D004417:Dyspnea / Q000401:mortality; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D011379:Prognosis; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000401:mortality*; D012129:Respiratory Function Tests; D012306:Risk; D012720:Severity of Illness Index