BACKGROUND: This study describes the characteristics of a large sample of patients hospitalised for the first time for a chronic obstructive pulmonary disease (COPD) exacerbation. METHODS: All subjects first admitted for a COPD exacerbation to nine teaching Spanish hospitals during January 2004-March 2006, were eligible. COPD diagnosis was confirmed by spirometry under stability. At admission, sociodemographic data, lifestyle, previous treatment and diagnosis of respiratory disease, lung function and Charlson index of co-morbidity were collected. A comprehensive assessment, including dyspnea, lung function, six-minute walking test, and St. George's Respiratory Questionnaire (SGRQ), was completed 3 months after admission, during a clinically stable disease period. RESULTS: Three-hundred and forty-two patients (57% of the eligible) participated in the study: 93% males, mean (SD) age 68 (9) years, 42% current smokers, 50% two or more co-morbidities, 54% mild-to-moderate dyspnea, post-bronchodilator FEV(1) 52 (16)% of predicted (54% mild-to-moderate COPD in ATS/ERS stages), 6-min walking distance 440 m, total SGRQ score 37 (18), and 36% not report respiratory disease. The absence of a previous COPD diagnosis, positive bronchodilator test, female gender, older age, higher DLco and higher BMI were independently associated with less severe COPD. CONCLUSIONS: We show that the patients admitted after presenting with their first COPD exacerbation have a wide range of severity, with a large proportion of patients in the less advanced COPD stages.

The PAC-COPD study is funded by grants from Fondo de Investigación Sanitaria (FIS PI020541), Ministry of Health, Spain; Agència d’Avaluació de Tecnologia i Recerca Mèdiques (AATRM 035/20/02), Catalonia Government; Spanish Society of Pneumology and Thoracic Surgery (SEPAR 2002/137); Catalan Foundation of Pneumology (FUCAP 2003 Beca Marià Ravà); Red RESPIRA (RTIC C03/11); Red RCESP (RTICC03/09); Fondo de Investigación Sanitaria (PI052486); Fondo de Investigación Sanitaria (PI052302); Fundació La Marató de TV3 (num. 041110); Novartis Farmacèutica, Spain. CIBERESP and CIBERES are funded by the Instituto de Salud Carlos III, Ministry of Health, Spain. Judith Garcia Aymerich has a researcher contract from the Instituto de Salud Carlos III (CP05/00118), Ministry of Health, Spain. Jordi de Batlle had a predoctoral fellowship from the Instituto de Salud Carlos III (FI05/01022), Ministry of Health, Spain.