Abstract
Inhaled corticosteroids (ICS) adherence is important for asthma management. Current evidence on the impact of ICS adherence on outcomes is mostly based on correlational analyses of between-person data. Although it is widely acknowledged that asthma outcomes fluctuate over time, evidence on predictors of within-person change is scarce. We aimed to quantify these fluctuations and the longitudinal relationships between ICS adherence and outcomes at both between- and within-person levels.
A prospective cohort of persistent asthma patients in France and the UK (n=847, age 6−40 years) provided 3756 reports over up to 2 years via computer-assisted telephone interviews and text messages on ICS adherence, asthma control, reliever medication use and exacerbations. We examined adherence−outcome relationships via longitudinal models, controlling for confounders, including severity.
Considerable within-person variability was found for exacerbations (91%), asthma control (59%) and reliever use (52%); 431 (11.5%) reports signalled exacerbations and 2046 (54.5%) poor control. At between-person level, patients with higher average adherence were more likely to report asthma control (OR 1.25, 95% CI 1.06−1.47), but not asthma exacerbations (OR 0.99, 95% CI 0.87−1.12) or lower reliever use (b −0.0004, 95% CI −0.089−0.088). At within-person level, higher-than-usual adherence was associated with higher concomitant reliever use (b 0.092, 95% CI 0.053−0.131) and lower subsequent reliever use (b −0.047, 95% CI −0.005− −0.088); it was unrelated to asthma control (OR 0.93, 95% CI 0.84−1.02) or exacerbations (OR 1.04, 95% CI 0.94−1.16).
Patients maintaining high ICS adherence over time have better asthma control. Temporarily increasing ICS adherence tends to be simultaneous to higher reliever use and reduces reliever use later on. Causes of within-person variation in outcomes require more investigation.
Abstract
Cohort study in routine care finds large variability in asthma outcomes over time. Patients with higher mean ICS adherence report better asthma control. ICS adherence and reliever use tend to increase at the same time and reduce use of relievers later on. http://bit.ly/2kK1bbv
Footnotes
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Members of the ASTRO-LAB group were: Marijn de Bruin, Alexandra L. Dima (ASCoR, University of Amsterdam, the Netherlands); Eric Van Ganse, Laurent Laforest, Sandrine Herbage, Manon Belhassen, Marine Ginoux, Flore Jacoud, Maeva Nolin (University Claude Bernard Lyon 1, France); Stéphane Schück, Nathalie Texier, Sandy Leproust, Hélène Le Cloarec (Kappa Santé, France); Richard Hubbard (University of Nottingham, UK); Alison Bourke, Mary Thompson, Delphine Vial, David Ansell (Cegedim Strategic Data, UK); Javier Olaiz, Ana Valcarcel Orti (Lyon Ingénierie Projets, France); and Montse Ferrer, Olatz Garin, Gimena Hernandez (IMIM - Hospital del Mar Medical Research Institute, Spain).
Conflict of interest: A.L. Dima reports grants from European Commission (European Community's 7th Framework (FP7/2007-2013) under grant agreement number 282593 and H2020 programme (MSCA-IF) under grant agreement number 706028), during the conduct of the study; grants and non-financial support from Respiratory Effectiveness Group, outside the submitted work.
Conflict of interest: E. van Ganse reports grants from European Commission (European Community's 7th Framework (FP7/2007-2013) under grant agreement number 282593), during the conduct of the study; grants and personal fees from ALK ABELLO, Bayer, BMS, GlaxoSmithKline and Merck Sharp and Dohme, personal fees from PELyon, outside the submitted work.
Conflict of interest: G. Stadler has nothing to disclose.
Conflict of interest: M. de Bruin reports grants from European Commission (European Community's 7th Framework (FP7/2007-2013) under grant agreement number 282593), during the conduct of the study.
Support statement: The research leading to these results has received funding from the European Community 7th Framework (FP7/2007-2013) under grant agreement number 282593, and H2020 programme (MSCA-IF) under grant agreement number 706028 for A.L. Dima during manuscript preparation. Funding information for this article has been deposited with the Crossref Funder Registry.
- Received May 5, 2019.
- Accepted September 16, 2019.
- Copyright ©ERS 2019