Members of the SMART Study Group are listed in the Appendix.
Metrics of salbutamol use as predictors of future adverse outcomes in asthma
Article first published online: 16 SEP 2013
© 2013 John Wiley & Sons Ltd
Clinical & Experimental Allergy
Volume 43, Issue 10, pages 1144–1151, October 2013
How to Cite
Clinical & Experimental Allergy, 2013 (43) 1144–1151., , , , , , , , ,
- Issue published online: 16 SEP 2013
- Article first published online: 16 SEP 2013
- Accepted manuscript online: 27 JUN 2013 09:32AM EST
- Manuscript Accepted: 21 JUN 2013
- Manuscript Revised: 18 JUN 2013
- Manuscript Received: 19 APR 2013
- Health Research Council of New Zealand
- electronic monitoring;
Beta-agonist overuse is associated with adverse outcomes in asthma, however, the relationships between different metrics of salbutamol use and future risk are uncertain.
To investigate the relationship between metrics of salbutamol use and adverse outcome.
In a 24-week randomized controlled trial of 303 asthma patients at risk of severe exacerbations which compared the efficacy and safety of combination budesonide/formoterol inhaler according to a single inhaler regimen (SMART) with a fixed-dose regimen with salbutamol as reliever (‘Standard’), actual medication use was measured by electronic monitoring (Australian New Zealand Clinical Trials Registry Number ACTRN12610000515099). A nested cohort study explored the relationship between metrics of baseline salbutamol use over 2 weeks and future severe asthma exacerbations, poor asthma control (ACQ-5 ≥ 1.5) or ‘extreme’ salbutamol overuse (> 32 salbutamol actuations/24-h period).
Higher mean daily salbutamol use (per two actuations/day) [Odds ratio (OR) (95% CI) 1.24 (1.06–1.46)], higher days of salbutamol use (per 2 days in 2 weeks) [OR 1.15 (1.00–1.31)] and higher maximal 24-h use (per two actuations/day) [OR 1.09 (1.02–1.16)] were associated with future severe exacerbations. Higher mean daily salbutamol use was associated with future poor asthma control [OR 1.13 (1.02–1.26)]. Higher mean daily salbutamol use [OR 2.73 (1.84–4.07)], number of days of use [OR 1.46 (1.24–1.71)], and maximal daily use [OR 1.57 (1.31–1.89)] were associated with an increased risk of future extreme salbutamol overuse.
Conclusion and Clinical Relevance
Electronically recorded frequency of current salbutamol use is a strong predictor of risk of future adverse outcomes in asthma, with average daily use performing the best. These findings provide new information for clinicians considering metrics of salbutamol as predictors of future adverse outcomes in asthma.