Improved survival at low lung function in cystic fibrosis: cohort study from 1990 to 2007BMJ 2011; 342 doi: https://doi.org/10.1136/bmj.d1008 (Published 28 February 2011) Cite this as: BMJ 2011;342:d1008
- P M George, academic registrar in respiratory medicine1,
- W Banya, medical statistician2,
- N Pareek, specialist trainee in cardiology1,
- D Bilton, consultant respiratory physician and honorary senior lecturer13,
- P Cullinan, professor of occupational and environmental respiratory disease3,
- M E Hodson, professor of respiratory medicine31,
- N J Simmonds, consultant respiratory physician1
- 1Department of Cystic Fibrosis, Royal Brompton Hospital, London SW3 6NP, UK
- 2Department of Research and Development, Royal Brompton Hospital
- 3National Heart and Lung Institute, Imperial College London, London, UK
- Correspondence: N Simmonds
- Accepted 31 December 2010
Objectives To evaluate the survival of patients with cystic fibrosis whose lung function has deteriorated to a forced expiratory volume in one second (FEV1) below 30% predicted in the recent treatment era and to explore factors associated with any change in survival.
Design Cohort study.
Setting Adult cystic fibrosis unit in London.
Participants 276 patients (147 (53%) male) whose FEV1 was first observed to be less than 30% predicted between 1 January 1990 and 31 December 2003.
Main outcome measure Survival during follow-up to 31 December 2007 in two year sub-cohorts.
Results Median survival improved from 1.2 years in the 1990-1 group to 5.3 years in the 2002-3 group, with a marked improvement in survival from 1994. The use of nebulised recombinant human DNase was significantly associated with a reduced risk of death (hazard ratio 0.59, 95% confidence interval 0.44 to 0.79). Significantly increased risks were associated with a body mass index under 19 (hazard ratio 1.52, 1.10 to 2.10), long term oxygen therapy (3.52, 2.49 to 4.99), and nebulised antibiotics (1.84, 1.05 to 3.22).
Conclusion A marked improvement has occurred in the survival of patients with cystic fibrosis with an FEV1 less than 30% predicted. Secondary analyses suggest that some of this improvement may be due to use of recombinant human DNase.
The study was supported by the Respiratory Biomedical Research Unit (BRU) at the Royal Brompton Hospital; MEH, DB, and NJS are part of the Chronic Suppurative Lung Disease (CSLD) research consortium of the Respiratory BRU. We acknowledge the input of Khin Gyi for supporting the data collection process that proved invaluable to the study.
Contributors: PMG contributed to conception and design, acquisition of data, analysis and interpretation of data, drafting the article, and final approval of the version to be published. WB contributed to design, statistical analysis and interpretation of data, and final approval of the version to be published. NP contributed to design, acquisition and analysis of data, and final approval of the version to be published. DB contributed to the conception, design, analysis and interpretation of the data, and final approval of the version to be published. PC contributed to design, statistical analysis and interpretation of data, drafting the article, and final approval of the version to be published. MEH contributed to conception and design, analysis and interpretation of data, and final approval of the version to be published. NJS contributed to conception and design, acquisition of data, analysis and interpretation of data, drafting the article, and coordinating the study. NJS is the guarantor.
Funding: No external funding.
Competing interests: All authors have completed the Unified Competing Interest form at www.icmje.org/coi_disclosure.pdf (available on request from the corresponding author) and declare that they have no relationships with any company that might have an interest in the submitted work in the previous 3 years; nor do their spouses, partners, or children have any financial relationships that may be relevant to the submitted work; and they have no non-financial interests that may be relevant to the submitted work.
Ethical approval: The Royal Brompton Hospital Ethics Committee has approved use of the data for this purpose.
Data sharing: No additional data available.
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