title: Asthma controller delay and recurrence risk after an emergency department visit or hospitalization.
abstract: BACKGROUND
  Patients who have asthma-related emergency department (ED) visits or hospitalizations are at risk for recurrent exacerbation events. Our objectives were to assess whether receiving a controller medication at discharge affects risk of recurrence and whether delaying controller initiation alters this risk.
  
  
  METHODS
  Asthma patients with an ED visit or inpatient (IP) stay who received a controller dispensing within 6 months were identified from healthcare claims. Cox proportional hazards of the time to first recurrence of an asthma-related ED or IP visit in the 6-month period following the initial event were constructed, with time following discharge without controller medication as the primary predictor.
  
  
  RESULTS
  A total of 6139 patients met inclusion criteria, 78% with an ED visit and 22% with an IP visit; 15% had a recurrence within 6 months. The adjusted hazard ratio (HR) associated with not having controller medication at discharge was 1.79 (95% confidence interval [CI], 1.42-2.25). The controller-by-time interaction was significant (P<0.001), with hazard rising as time-to-controller initiation increased. Delaying initiation by 1 day approximately tripled the risk (HR 2.95; 95%CI 1.48-5.88). Sensitivity analyses, including accounting for controller fills prior to the index event, did not substantially alter these results.
  
  
  CONCLUSIONS
  This observational study shows that the risk of a recurrent asthma-related ED visit or IP stay increased as the time to initiate a controller increased. Our findings support the importance of early controller initiation following an asthma-related ED or IP visit in reducing risk of recurrence.
authors.affiliation: US Health Outcomes, GlaxoSmithKline, Five Moore Drive, Research Triangle Park, NC 27709, USA. richard.h.stanford@gsk.com
authors.forename: Richard H
authors.initials: RH
authors.lastname: Stanford
authors.forename: Ami R
authors.initials: AR
authors.lastname: Buikema
authors.forename: Aylin A
authors.initials: AA
authors.lastname: Riedel
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Camargo
authors.forename: Gabriel Gomez
authors.initials: GG
authors.lastname: Rey
authors.forename: Kenneth R
authors.initials: KR
authors.lastname: Chapman
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D018927:Anti-Asthmatic Agents / Q000008:administration & dosage*; D001249:Asthma / Q000517:prevention & control*; D002648:Child; D002675:Child, Preschool; D018450:Disease Progression; D004630:Emergencies; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010342:Patient Acceptance of Health Care; D018570:Risk Assessment; D012307:Risk Factors; D012621:Seasons; D055502:Secondary Prevention; D061665:Time-to-Treatment; D055815:Young Adult
chemical_list: D018927:Anti-Asthmatic Agents