title: One-year outcomes of inhaled controller therapies added to systemic corticosteroids after asthma-related hospital discharge.
abstract: BACKGROUND
  Much of the evidence on the early use of inhaled controllers after severe asthma exacerbations is about their short-term benefit, leaving a gap in evidence on their longer-term outcomes.
  
  
  METHODS
  We used administrative health data from British Columbia, Canada (2001-2012) to evaluate readmission rate (primary outcome), adherence to controller medications, and use of reliever medications associated with different inhaled controller treatments as an add-on to systemic corticosteroids (SCS) over one-year following discharge from an asthma-related admission in individuals 12-55 years of age. Exposure was assessed in the 60 days after discharge, and categorized as monotherapy with SCS (SCS-only) versus SCS plus inhaled controller therapy (SCS + inhaler); the latter was further divided into SCS + inhaled corticosteroid (SCS + ICS) and SCS + ICS and long-acting beta agonists (SCS + ICS/LABA). Propensity score-adjusted regression models were used to estimate relative rates (RR) of outcomes across exposure groups.
  
  
  RESULTS
  The final cohort included 2,272 post-discharge periods (43.0% SCS-only, 26.9% SCS + ICS, and 30.1% SCS + ICS/LABA). Readmission rate was significantly lower in the SCS + inhaler versus SCS-only (RR = 0.74 [95%CI 0.59-0.93]), but similar between SCS + ICS and SCS + ICS/LABA (RR = 0.78 [95%CI 0.59-1.04]). Long-term adherence, defined as medication possession ratio, to controller medications was 83% higher in SCS + inhaler than SCS-only, and 64% higher in SCS + ICS/LABA than in SCS + ICS. The use of reliever medications was similar across exposure groups.
  
  
  CONCLUSIONS
  Early initiation of inhaled controllers after discharge from an asthma-related hospitalization was associated with significantly better long-term adherence to controller medications as well as reduced rate of readmissions. Combination therapy with ICS/LABA seems to be at least as effective as mono-therapy with ICS in reducing the risk of readmission, with the added benefit of better long-term adherence.
authors.affiliation: Institute for Heart and Lung Health, Department of Medicine, The University of British Columbia, Vancouver, Canada; Centre for Clinical Epidemiology and Evaluation, The University of British Columbia, Vancouver, Canada. Electronic address: msafavi@mail.ubc.ca.
authors.forename: Mohsen
authors.initials: M
authors.lastname: Sadatsafavi
authors.affiliation: Collaboration for Outcomes Research and Evaluation, Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, Canada; Centre for Health Evaluation and Outcome Sciences, The University of British Columbia, Vancouver, Canada.
authors.forename: Larry D
authors.initials: LD
authors.lastname: Lynd
authors.affiliation: Collaboration for Outcomes Research and Evaluation, Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, Canada.
authors.forename: Mary A
authors.initials: MA
authors.lastname: De Vera
authors.affiliation: Centre for Health Evaluation and Outcome Sciences, The University of British Columbia, Vancouver, Canada.
authors.forename: Zafar
authors.initials: Z
authors.lastname: Zafari
authors.affiliation: Institute for Heart and Lung Health, Department of Medicine, The University of British Columbia, Vancouver, Canada; Centre for Clinical Epidemiology and Evaluation, The University of British Columbia, Vancouver, Canada.
authors.forename: J Mark
authors.initials: JM
authors.lastname: FitzGerald
mesh_terms: D000280:Administration, Inhalation; D000293:Adolescent; D000328:Adult; D001249:Asthma / Q000188:drug therapy* / Q000453:epidemiology* / Q000401:mortality; D002170:Canada / Q000453:epidemiology; D002648:Child; D015331:Cohort Studies; D004305:Dose-Response Relationship, Drug; D011307:Drug Prescriptions / Q000706:statistics & numerical data*; D005260:Female; D005500:Follow-Up Studies; D005938:Glucocorticoids / Q000008:administration & dosage / Q000627:therapeutic use*; D006801:Humans; D007902:Length of Stay; D008297:Male; D016347:Medical Records Systems, Computerized; D008875:Middle Aged; D009330:Nebulizers and Vaporizers; D010351:Patient Discharge / Q000706:statistics & numerical data*; D010359:Patient Readmission / Q000706:statistics & numerical data*; D016896:Treatment Outcome
chemical_list: D005938:Glucocorticoids
keywords: Asthma; Comparative effectiveness; Outcomes; Propensity score; Resource use; Treatment