Risk factors of readmission to hospital for a COPD exacerbation: a prospective study
- J Garcia-Aymerich1,
- E Farrero2,
- M A Félez3,
- J Izquierdo4,
- R M Marrades5,
- J M Antó1,6,
- on behalf of the EFRAM investigators*
- 1Respiratory and Environmental Health Research Unit, IMIM, Barcelona, Spain
- 2Department of Pneumology, Ciutat Sanitària I Universitària de Bellvitge, L’Hospitalet de Llobregat, Spain
- 3Department of Pneumology, Hospital del Mar, Barcelona, Spain
- 4Department of Pneumology, Hospital Germans Trias I Pujol, Badalona, Spain
- 5Department of Pneumology, Hospital Clínic I Provincial de Barcelona, Barcelona, Spain
- 6Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona, Spain
- Correspondence to:
Dr J M Antó, Respiratory and Environmental Health Research Unit, Institut Municipal d’Investigació Mèdica (IMIM), Doctor Aiguader 80, E-08003 Barcelona, Spain; e-mail
- Accepted 21 October 2002
- Revised 25 September 2002
Background: Exacerbations of chronic obstructive pulmonary disease (COPD) are a leading cause of admission to hospital among men in many countries, although the factors causing exacerbations are largely unknown. The association between readmission for a COPD exacerbation and a wide range of modifiable potential risk factors, after adjusting for sociodemographic and clinical factors, has been assessed.
Methods: Three hundred and forty patients with COPD recruited during an admission for an exacerbation in four tertiary hospitals in the Barcelona area of Spain were followed for a mean period of 1.1 years. Information on potential risk factors, including clinical and functional status, medical care and prescriptions, medication adherence, lifestyle, health status, and social support, was collected at the recruitment admission. A Cox’s proportional hazards model was used to obtain independent relative risks of readmission for COPD.
Results: During the follow up period 63% of patients were readmitted at least once, and 29% died. The final multivariate model showed the following risk (or protective) factors: ⩾3 admissions for COPD in the year before recruitment (hazard ratio (HR)=1.66, 95% CI 1.16 to 2.39), forced expiratory volume in 1 second (FEV1) percentage predicted (0.97, 95% CI 0.96 to 0.99), oxygen tension (0.88, 95% CI 0.79 to 0.98), higher levels of usual physical activity (0.54, 95% CI 0.34 to 0.86), and taking anticholinergic drugs (1.81, 95% 1.11 to 2.94). Exposure to passive smoking was also related to an increased risk of readmission with COPD after adjustment for clinical factors (1.63, 95% CI 1.04 to 2.57) but did not remain in the final model.
Conclusions: This is the first study to show a strong association between usual physical activity and reduced risk of readmission to hospital with COPD, which is potentially relevant for rehabilitation and other therapeutic strategies.
↵* EFRAM: Estudi dels Factors de Risc d’Agudització de la MPOC (Risk Factors of COPD Exacerbation Study).
EFRAM investigators: J M Antó, J Garcia-Aymerich, J Sunyer, Respiratory and Environmental Health Research Unit, IMIM, Barcelona; J Alonso, Health Services Research Unit, IMIM, Barcelona; E Barreiro, M A Félez, Department of Pneumology, Hospital del Mar, Barcelona; J Escarrabill, E Farrero, J Redondo, Department of Pneumology, Ciutat Sanitària I Universitària de Bellvitge, L’Hospitalet de Llobregat; R M Marrades, N Soler, A Torres, Department of Pneumology, Hospital Clínic I Provincial de Barcelona, Barcelona; G Bonet, J Izquierdo, E Monsó, J Morera, Department of Pneumology, Hospital Germans Trias I Pujol, Badalona.
This work was supported in part by grants from Agència d’Avaluació de Tecnologia Mèdica (5/34/96) and Generalitat de Catalunya-CIRIT 1999SGR 00241; J Garcia-Aymerich was a recipient of a grant from Instituto de Salud “Carlos III” (97/4365) from 1997 to 2000 and currently has a fellowship from Institut Municipal d’Investigació Mèdica.
Conflict of interest: none.