Back to Journals » Journal of Asthma and Allergy » Volume 9

Predicting frequent asthma exacerbations using blood eosinophil count and other patient data routinely available in clinical practice

Authors Price DB, Wilson A, Chisholm A, Rigazio A, Burden A, Thomas M, King C

Received 12 October 2015

Accepted for publication 12 November 2015

Published 7 January 2016 Volume 2016:9 Pages 1—12


Checked for plagiarism Yes

Review by Single-blind

Peer reviewers approved by Dr Ramin Nazari

Peer reviewer comments 2

Editor who approved publication: Dr Amrita Dosanjh

David Price,1,2 Andrew M Wilson,3 Alison Chisholm,4 Anna Rigazio,2 Anne Burden,2 Michael Thomas,5 Christine King2

1Centre for Academic Primary Care, The Institute of Applied Health Sciences, University of Aberdeen, Aberdeen, 2Research in Real-Life, Cambridge, 3Norwich Medical School, University of East Anglia, Norwich, 4Respiratory Effectiveness Group, Cambridge, 5Primary Medical Care, University of Southampton, Southampton, UK

Purpose: Acute, severe asthma exacerbations can be difficult to predict and thus prevent. Patients who have frequent exacerbations are of particular concern. Practical exacerbation predictors are needed for these patients in the primary-care setting.
Patients and methods: Medical records of 130,547 asthma patients aged 12–80 years from the UK Optimum Patient Care Research Database and Clinical Practice Research Datalink, 1990–2013, were examined for 1 year before (baseline) and 1 year after (outcome) their most recent blood eosinophil count. Baseline variables predictive (P<0.05) of exacerbation in the outcome year were compared between patients who had two or more exacerbations and those who had no exacerbation or only one exacerbation, using uni- and multivariable logistic regression models. Exacerbation was defined as asthma-related hospital attendance/admission (emergency or inpatient) or acute oral corticosteroid (OCS) course.
Results: Blood eosinophil count >400/µL (versus ≤400/µL) increased the likelihood of two or more exacerbations >1.4-fold (odds ratio [OR]: 1.48 (95% confidence interval [CI]: 1.39, 1.58); P<0.001). Variables that significantly increased the odds by up to 1.4-fold included increasing age (per year), female gender (versus male), being overweight or obese (versus normal body mass index), being a smoker (versus nonsmoker), having anxiety/depression, diabetes, eczema, gastroesophageal reflux disease, or rhinitis, and prescription for acetaminophen or nonsteroidal anti-inflammatory drugs. Compared with treatment at British Thoracic Society step 2 (daily controller ± reliever), treatment at step 0 (none) or 1 (as-needed reliever) increased the odds by 1.2- and 1.6-fold, respectively, and treatment at step 3, 4, or 5 increased the odds by 1.3-, 1.9-, or 3.1-fold, respectively (all P<0.05). Acute OCS use was the single best predictor of two or more exacerbations. Even one course increased the odds by more than threefold (OR: 3.75 [95% CI: 3.50, 4.01]; P<0.001), and three or more courses increased the odds by >25-fold (OR: 25.7 [95% CI: 23.9, 27.6]; P<0.001).
Conclusion: Blood eosinophil count and several other variables routinely available in patient records may be used to predict frequent asthma exacerbations.

Keywords: exacerbator, risk, multiple, hospitalization

Creative Commons License This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at and incorporate the Creative Commons Attribution - Non Commercial (unported, v3.0) License. By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms.

Download Article [PDF]  View Full Text [HTML][Machine readable]


Other articles by this author:

Long-acting muscarinic antagonist use in adults with asthma: real-life prescribing and outcomes of add-on therapy with tiotropium bromide

Price D, Kaplan A, Jones R, Freeman D, Burden A, Gould S, von Ziegenweidt J, Ali M, King C, Thomas M

Journal of Asthma and Allergy 2015, 8:1-13

Published Date: 14 January 2015

Switching patients from other inhaled corticosteroid devices to the Easyhaler®: historical, matched-cohort study of real-life asthma patients

Price D, Thomas V, von Ziegenweidt J, Gould S, Hutton C, King C

Journal of Asthma and Allergy 2014, 7:31-51

Published Date: 10 April 2014

Readers of this article also read:

Step-down therapy in well-controlled asthmatic patients using salmeterol xinafoate/fluticasone propionate combination therapy

Horiuchi K, Kasahara K, Kuroda Y, Morohoshi H, Hagiwara Y, Ishii G

Journal of Asthma and Allergy 2016, 9:65-70

Published Date: 18 March 2016

Challenges in the management of severe allergic asthma in the elderly

Ozturk AB, Iliaz S

Journal of Asthma and Allergy 2016, 9:55-63

Published Date: 17 March 2016

The asthma–COPD overlap syndrome: how is it defined and what are its clinical implications?

van den Berge M, Aalbers R

Journal of Asthma and Allergy 2016, 9:27-35

Published Date: 10 February 2016

Wheat allergy: diagnosis and management

Cianferoni A

Journal of Asthma and Allergy 2016, 9:13-25

Published Date: 29 January 2016