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Variability of antibiotic prescribing in patients with chronic obstructive pulmonary disease exacerbations: a cohort study

Rachael Boggon12, Richard Hubbard3, Liam Smeeth4, Martin Gulliford5, Jackie Cassell6, Susan Eaton1, Munir Pirmohamed7 and Tjeerd-Pieter van Staa124*

Author Affiliations

1 Clinical Practice Research Datalink, Medicines and Healthcare products Regulatory Agency, 151 Buckingham Palace Road, London SW1W 9SZ, UK

2 Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, the Netherlands

3 Division of Epidemiology and Public Health, Nottingham University, Nottingham, UK

4 London School of Hygiene & Tropical Medicine, London, UK

5 Primary Care and Public Health Sciences, King’s College, London, UK

6 Division of Primary Care and Public Health, Brighton and Sussex Medical School, University of Brighton, Brighton, UK

7 The Wolfson Centre for Personalised Medicine, Institute of Translational Medicine, University of Liverpool, Liverpool, UK

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BMC Pulmonary Medicine 2013, 13:32  doi:10.1186/1471-2466-13-32

Published: 31 May 2013



The role of antibiotics in treating mild or moderate exacerbations in patients with acute chronic obstructive pulmonary disease (COPD) is unclear. The aims were to: (i) describe patient characteristics associated with acute exacerbations amongst a representative COPD population, (ii) explore the relationship between COPD severity and outcomes amongst patients with exacerbations, and (iii) quantify variability by general practice in prescribing of antibiotics for COPD exacerbations.


A cohort of 62,747 patients with COPD was identified from primary care general practices (GP) in England, and linked to hospital admission and death certificate data. Exacerbation cases were matched to three controls and characteristics compared using conditional logistic regression. Outcomes were compared using incidence rates and Cox regression, stratified by disease severity. Variability of prescribing at the GP level was evaluated graphically and by using multilevel models.


COPD severity was found to be associated with exacerbation and subsequent mortality (very severe vs. mild, odds ratio for exacerbation 2.12 [95%CI 19.5–2.32]), hazard ratio for mortality 2.14 [95%CI 1.59–2.88]). Whilst 61% of exacerbation cases were prescribed antibiotics, this proportion varied considerably between GP practices (interquartile range, 48–73%). This variation is greater than can be explained by patient characteristics alone.


There is significant variability between GP practices in the prescribing of antibiotics to COPD patients experiencing exacerbations. Combined with a lack of evidence on the effects of treatment, this supports the need and opportunity for a large scale pragmatic randomised trial of the prescribing of antibiotics for COPD patients with exacerbations, in order to clarify their effectiveness and long term outcomes whilst ensuring the representativeness of subjects.

Chronic obstructive pulmonary disease; Disease exacerbation; Clinical practice variation; Anti-bacterial agents; Primary health care; General practice