There is little information available concerning the extent to which chronic obstructive pulmonary disease (COPD) patients are satisfactorily managed, especially, regards factors supposedly related to COPD exacerbation. The present study assessed the prevalence rates of potentially modifiable risk factors of COPD exacerbation in patients hospitalized for this reason.A systematic sample of one out of two patients admitted for COPD exacerbation, during 1 yr, in four tertiary hospitals in the Barcelona area, Spain, was performed. Patients answered a questionnaire and underwent anthropometric measurements, spirometric tests and arterial blood gas sampling. Prevalence rates and 95% confidence intervals (95% CI) for risk factors were obtained, and the generalized estimating equation (GEE) method was used to allow for patients to provide information on different admissions.The study recruited 353 patients (29 female) with a total of 404 admissions age (mean SD) 69 9, median forced expiratory volume in one second (FEV1) 31% of predicted and mean partial pressure of oxygen (PO 2 ) 63 13 mmHg. Of these, 28% had not received an influenza vaccination; a high number (86%) did not attend rehabilitation programmes; 28% of patients with PO 2 #55 mmHg were not using long-term oxygen therapy (LTOT); among LTOT users, 18% used it <15 h a day; 43% of the total failed in some of the essential inhaler manoeuvres; 26% were current smokers; 21% of noncurrent smokers were exposed to passive smoking at home; current occupational exposure was low (5%).In summary, the authors found a moderate to high prevalence of potentially modifiable risk factors in a large representative sample of patients hospitalized for a chronic obstructive pulmonary disease exacerbation, suggesting unsatisfactory features in their management. Eur Respir J 2000; 16: 1037±1042. Chronic obstructive pulmonary disease (COPD) is characterized by a chronic slowly progressive limitation of the airflow. As the damage is largely irreversible, the major goals of COPD management are to lessen airflow limitation, prevent and decrease symptoms, prevent and treat medical complications and improve daily living and quality of life [1]. The acute exacerbation of COPD is among the relevant events in the progression of the disease, and its occurrence has been related to the lower survival [2] and decrease in the quality of life [3] of COPD patients. Acute exacerbations are also an important cause of health expenditure, due to hospitalization, outpatient care and drug consumption [1].Although respiratory infection is assumed to be the main risk factor for the exacerbation of COPD [4], other factors are also involved. Health education of patients, smoking cessation, pulmonary rehabilitation, good nutritional status, and early medical intervention are all considered helpful in preventing exacerbations [5]. Information concerning the extent to which COPD patients are satisfactorily managed with regards these factors, although likely to show strong local variations, is relevant ...