Predictors of pulmonary exacerbations in patients with cystic fibrosis infected with multi-resistant bacteria
- J K Block1,
- K L Vandemheen1,
- E Tullis3,
- D Fergusson1,
- S Doucette1,
- D Haase4,
- Y Berthiaume5,
- N Brown6,
- P Wilcox7,
- P Bye2,
- S Bell8,
- M Noseworthy9,
- L Pedder10,
- A Freitag10,
- N Paterson11,
- S D Aaron1
- 1Ottawa Health Research Institute, University of Ottawa, Ottawa, ON, Canada
- 2Woolcock Institute, Sydney, NSW, Australia
- 3St Michael’s Hospital, Toronto, ON, Canada
- 4Dalhousie University, Halifax, NS, Canada
- 5Universite de Montreal, Montreal, QC, Canada
- 6University of Alberta, Edmonton, AB, Canada
- 7University of British Columbia, Vancouver, BC, Canada
- 8The Prince Charles Hospital, Brisbane, Qld, Australia
- 9Memorial University, St John’s, NF, Canada
- 10McMaster University, Hamilton, ON, Canada
- 11University of Western Ontario, London, ON, Canada
- Correspondence to:
Dr S D Aaron
Ottawa Hospital, General Campus, 501 Smyth Road, Mailbox 211, Ottawa, Ontario, Canada K1H 8L6; saaron{at}ottawahospital.on.ca
- Received 24 February 2006
- Accepted 3 July 2006
- Published Online First 14 July 2006
Abstract
Background: This study examined characteristics of adult and adolescent patients with cystic fibrosis (CF) to determine factors associated with an increased risk of pulmonary exacerbations.
Methods: 249 patients with CF infected with multidrug resistant bacteria were recruited and prospectively followed for up to 4.5 years until they experienced a pulmonary exacerbation severe enough to require intravenous antibiotics. Multivariable regression analyses were used to compare the characteristics of patients who experienced an exacerbation with those who did not.
Results: 124 of the 249 patients (50%) developed a pulmonary exacerbation during the first year and 154 (62%) experienced an exacerbation during the 4.5 year study period. Factors predictive of exacerbations in a multivariable survival model were younger age (OR 0.98, 95% CI 0.96 to 0.99), female sex (OR 1.45, 95% CI 1.07 to 1.95), lower forced expiratory volume in 1 second (FEV1) (OR 0.98, 95% CI 0.97 to 0.99), and a previous history of multiple pulmonary exacerbations (OR 3.16, 95% CI 1.93 to 5.17). Chronic use of inhaled corticosteroids was associated with an increased risk of exacerbation (OR 1.92, 95% CI 1.00 to 3.71) during the first study year.
Conclusions: Patients who experience pulmonary exacerbations are more likely to be younger, female, using inhaled steroids, have a lower FEV1, and a history of multiple previous exacerbations. It is hoped that knowledge of these risk factors will allow better identification and closer monitoring of patients who are at high risk of exacerbations.
- BMI, body mass index
- CF, cystic fibrosis
- FEV1, forced expiratory volume in 1 second
- FVC, forced vital capacity
Footnotes
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Published Online First 14 July 2006
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Supported by grants from The Canadian Institutes of Health Research, The Australian Cystic Fibrosis Research Trust, Astra-Zeneca Canada Inc (unrestricted research grant), and The Canadian Cystic Fibrosis Foundation.
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Competing interests: none declared.









