title: Clinical application of the COPD assessment test: longitudinal data from the COPD History Assessment in Spain (CHAIN) cohort.
abstract: OBJECTIVE
  The COPD Assessment Test (CAT) has been proposed for assessing health status in COPD, but little is known about its longitudinal changes. The objective of this study was to evaluate 1-year CAT variability in patients with stable COPD and to relate its variations to changes in other disease markers.
  
  
  METHODS
  We evaluated the following variables in smokers with and without COPD at baseline and after 1 year: CAT score, age, sex, smoking status, pack-year history, BMI, modified Medical Research Council (mMRC) scale, 6-min walk distance (6MWD), lung function, BODE (BMI, obstruction, dyspnea, exercise capacity) index, hospital admissions, Hospital and Depression Scale, and the Charlson comorbidity index. In patients with COPD, we explored the association of CAT scores and 1-year changes in the studied parameters.
  
  
  RESULTS
  A total of 824 smokers with COPD and 126 without COPD were evaluated at baseline and 441 smokers with COPD and 66 without COPD 1 year later. At 1 year, CAT scores for patients with COPD were similar (± 4 points) in 56%, higher in 27%, and lower in 17%. Of note, mMRC scale scores were similar (± 1 point) in 46% of patients, worse in 36%, and better in 18% at 1 year. One-year CAT changes were best predicted by changes in mMRC scale scores (β-coefficient, 0.47; P < .001). Similar results were found for CAT and mMRC scale score in smokers without COPD.
  
  
  CONCLUSIONS
  One-year longitudinal data show variability in CAT scores among patients with stable COPD similar to mMRC scale score, which is the best predictor of 1-year CAT changes. Further longitudinal studies should confirm long-term CAT variability and its clinical applicability.
  
  
  BACKGROUND
  ClinicalTrials.gov; No.: NCT01122758; URL: www.clinicaltrials.gov.
authors: Pulmonary Department, Clínica Universidad de Navarra, Pamplona, Spain. Electronic address: jupa65@hotmail.com.
authors: Juan P
authors: JP
authors: de Torres
authors: Pulmonary Department, Hospital Universitario Miguel Servet, Zaragoza, Spain; CIBER de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III, Madrid, Spain.
authors: Jose M
authors: JM
authors: Marin
authors: Pulmonary Department, Hospital Central de Asturias, Oviedo, Spain.
authors: Cristina
authors: C
authors: Martinez-Gonzalez
authors: Pulmonary Department I, Hospital Gregorio Marañon, Madrid, Spain.
authors: Pilar
authors: P
authors: de Lucas-Ramos
authors: Pulmonary Department, Hospital Son Llátzer, Palma de Mallorca, Madrid, Spain.
authors: Isabel
authors: I
authors: Mir-Viladrich
authors: Pulmonary Department, Hospital Son Espases, Palma de Mallorca, Madrid, Spain; CIBER de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III, Madrid, Spain.
authors: Borja
authors: B
authors: Cosio
authors: Pulmonary Department, Fundación Jimenez Diaz, Madrid, Spain; CIBER de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III, Madrid, Spain.
authors: German
authors: G
authors: Peces-Barba
authors: Pulmonary Department, Hospital Clinico San Carlos, Madrid, Spain.
authors: Miryam
authors: M
authors: Calle-Rubio
authors: Pulmonary Department, Hospital San Pablo y la Santa Cruz, Barcelona, Spain.
authors: Ingrid
authors: I
authors: Solanes-García
authors: Pulmonary Department, Hospital Marques de Valdecilla, Santander, Spain.
authors: Ramón
authors: R
authors: Agüero Balbin
authors: Pulmonary Department, Hospital Universitario y Politécnico La Fe, Valencia, Spain.
authors: Alfredo
authors: A
authors: de Diego-Damia
authors: Pulmonary Department, Hospital Universitario Reina Sofía, Cordoba, Spain.
authors: Nuria
authors: N
authors: Feu-Collado
authors: Pulmonary Department, Hospital Universitario de Valme, Sevilla, Spain.
authors: Inmaculada
authors: I
authors: Alfageme Michavila
authors: Pulmonary Department, Hospital de Manacor, Mallorca, Spain.
authors: Rosa
authors: R
authors: Irigaray
authors: Pulmonary Department, Hospital del Mar, Barcelona, Spain; CIBER de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III, Madrid, Spain.
authors: Eva
authors: E
authors: Balcells
authors: Pulmonary Department, Hospital de Terrassa, Terrassa, Spain.
authors: Antònia
authors: A
authors: Llunell Casanovas
authors: Pulmonary Department, Hospital de Cruces, UPV/EHU, Bilbao, Spain; CIBER de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III, Madrid, Spain.
authors: Juan Bautista
authors: JB
authors: Galdiz Iturri
authors: Pulmonary Department, Hospital General de Castellón, Castellón, Spain.
authors: Margarita
authors: M
authors: Marín Royo
authors: Pulmonary Department, Hospital General de Requena, Valencia, Spain; CIBER de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III, Madrid, Spain.
authors: Juan J
authors: JJ
authors: Soler-Cataluña
authors: Unidad Médico-Quirúrgica de Enfermedades Respiratorias, Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío, Sevilla, Spain; CIBER de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III, Madrid, Spain.
authors: Jose Luis
authors: JL
authors: Lopez-Campos
authors: Epidemiology and Clinical Research, CIMERA, Bunyola, Mallorca, Spain.
authors: Joan B
authors: JB
authors: Soriano
authors: Pulmonary Department, Hospital Universitario Nuestra Señora de Candelaria, Tenerife, Spain.
authors: Ciro
authors: C
authors: Casanova
mesh_terms: D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology; D005500:Follow-Up Studies; D006304:Health Status; D009017:Morbidity / Q000639:trends; D011379:Prognosis; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology; D018570:Risk Assessment / Q000379:methods; D012720:Severity of Illness Index; D013030:Spain / Q000453:epidemiology; D013997:Time Factors