title: Use of ICS/LABA on Asthma Exacerbation Risk in Patients Within a Medical Group.
abstract: BACKGROUND
  Asthma medication ratio (AMR) ≥ 0.5 has been shown to predict asthma exacerbations. This study explores the impact of increasing or decreasing inhaled corticosteroid/long-acting beta-agonist (ICS/LABA) use over a 7-year period on achieving an AMR of ≥ 0.5.
  
  
  OBJECTIVE
  To (a) assess the impact of increasing use of ICS/LABAs on changes in a modified AMR (mAMR) and (b) examine asthma risk over time as measured by an mAMR over a 7-year period, adjusting for differences in baseline characteristics.
  
  
  METHODS
  This is a retrospective, observational study using pharmacy and medical claims from a medical group from January 1, 2003, to December 31, 2010. All patients with ≥ 1 asthma diagnosis (ICD-9-CM, 493.xx) with ≥ 1 inhaled asthma medication dispensed in each year of eligibility were included. The mAMR = total ICS controllers dispensed/(total ICS controllers dispensed + albuterol dispensed). The proportion of ICS/LABA use was determined as the number of ICS/LABA canisters dispensed/(total of ICS/LABA + ICS dispensed). Generalized linear mixed models were used to assess the effect of incremental change in ICS/LABA use on mAMR over 7 years, adjusting for differences in resource utilization, time, and asthma medication use.
  
  
  RESULTS
  Nine hundred ninety patients (mean age [± SD] 34.7 years [± 18.2], 61.7% female) met all criteria. Overall, mean mAMR increased over time, while mean albuterol use decreased over time. Adjusting for covariates, we found that a 10% increase in ICS/LABA use was associated with a 9% increase (adjusted OR = 1.09, 95% CI = 1.06-1.12) in the likelihood of achieving an mAMR ≥ 0.5, while a 50% increase in ICS/LABA use was associated with a 53% increase (OR = 1.53, 95% CI = 1.31-1.80) in the likelihood of achieving an mAMR ≥ 0.5.
  
  
  CONCLUSIONS
  Increase in ICS/LABA use over time in a population of asthma patients was significantly associated with a higher likelihood of achieving an mAMR ≥ 0.5.
authors.affiliation: GlaxoSmithKline, 5 Moore Dr., Research Triangle Park, NC 27709. richard.h.stanford@gsk.com.
authors.forename: Richard H
authors.initials: RH
authors.lastname: Stanford
authors.forename: Saurabh
authors.initials: S
authors.lastname: Nagar
authors.forename: Xiwu
authors.initials: X
authors.lastname: Lin
authors.forename: Richard D
authors.initials: RD
authors.lastname: O'Connor
mesh_terms: D000280:Administration, Inhalation; D000293:Adolescent; D000305:Adrenal Cortex Hormones / Q000008:administration & dosage*; D000318:Adrenergic beta-Agonists / Q000008:administration & dosage*; D000328:Adult; D018927:Anti-Asthmatic Agents / Q000008:administration & dosage*; D001249:Asthma / Q000188:drug therapy*; D003692:Delayed-Action Preparations; D005260:Female; D006801:Humans; D007345:Insurance Claim Review; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014481:United States; D055815:Young Adult
chemical_list: D000305:Adrenal Cortex Hormones; D000318:Adrenergic beta-Agonists; D018927:Anti-Asthmatic Agents; D003692:Delayed-Action Preparations