TY - JOUR T1 - Does adherence to inhaled corticosteroids predict asthma-related outcomes over time? A cohort study JF - European Respiratory Journal JO - Eur Respir J DO - 10.1183/13993003.00901-2019 SP - 1900901 AU - Alexandra L. Dima AU - Eric van Ganse AU - Gertraud Stadler AU - Marijn de Bruin AU - the ASTRO-LAB group Y1 - 2019/01/01 UR - http://erj.ersjournals.com/content/early/2019/09/19/13993003.00901-2019.abstract N2 - 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 United Kingdom (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 relations 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 [0.87−1.12] or lower reliever use (b=-.0004 [−0.089−0.088]). At within-person level, higher-than-usual adherence was associated with higher concomitant reliever use (b=0.092 [0.053−0.131]) and lower subsequent reliever use (b=−0.047 [−0.005− −0.088]); it was unrelated to asthma control (OR=0.93 [0.84−1.02]) or exacerbations (OR=1.04 [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.FootnotesThis manuscript has recently been accepted for publication in the European Respiratory Journal. It is published here in its accepted form prior to copyediting and typesetting by our production team. After these production processes are complete and the authors have approved the resulting proofs, the article will move to the latest issue of the ERJ online. Please open or download the PDF to view this article.Conflict of interest: Dr. Dima reports grants from European Commission, during the conduct of the study; grants and non-financial support from Respiratory Effectiveness Group, outside the submitted work.Conflict of interest: Dr. Van Ganse reports grants from European Commission, during the conduct of the study; grants and personal fees from ALK ABELLO, grants and personal fees from Bayer, grants and personal fees from BMS, grants and personal fees from GlaxoSmithKline, grants and personal fees from Merck Sharp and Dohme, personal fees from PELyon, outside the submitted work.Conflict of interest: Dr. Stadler has nothing to disclose.Conflict of interest: Dr. de Bruin reports grants from European Commission, during the conduct of the study. ER -