title: The impact of asthma medication guidelines on asthma controller use and on asthma exacerbation rates comparing 1997-1998 and 2004-2005.
abstract: BACKGROUND
  The relationship between asthma controller medication use and exacerbation rates over time is unclear at the population level.
  
  
  OBJECTIVE
  To estimate the change in asthma controller medication use between 2 time periods as measured by the controller-to-total asthma medication ratio and its association with changes in asthma exacerbation rates between 1997-1998 and 2004-2005.
  
  
  METHODS
  The study design was a cross-sectional population-level comparison between individuals from 1997-1998 and 2004-2005. Study participants were individuals aged 5 to 56 years identified as having asthma in the Medical Expenditure Panel Survey (MEPS). The main outcome measures were a controller-to-total asthma medication ratio greater than 0.5 and asthma exacerbation rates (dispensing of systemic corticosteroid or emergency department visit/hospitalization for asthma) in 1997-1998 compared with 2004-2005.
  
  
  RESULTS
  The proportion of individuals with a controller-to-total asthma medication ratio greater than 0.5, when adjusted for other demographic factors, has improved by 16.1% (95% CI: 10.8%, 21.3%) for all individuals from 1997-1998 to 2004-2005. Annual asthma exacerbation rates did not change significantly in any group from 1997-1998 to 2004-2005 (0.27/year to 0.23/year). African American and Hispanic individuals with asthma had higher asthma exacerbation rates and a lower proportion with a controller-to-total asthma medication ratio greater than 0.5 than whites in both 1997-1998 and 2004-2005; however, these differences were not statistically significant.
  
  
  CONCLUSIONS
  An increase in asthma controller-to-total medication ratio in a sample reflective of the US population was not associated with a decreased asthma exacerbation rate comparing 1997-1998 and 2004-2005.
authors.affiliation: Division of Allergic Diseases, Olmsted Medical Center, Rochester, MN. Electronic address: rank.matthew@mayo.edu.
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Rank
authors.affiliation: Division of Health Care Policy and Research, Olmsted Medical Center, Rochester, MN.
authors.forename: Juliette T
authors.initials: JT
authors.lastname: Liesinger
authors.affiliation: Division of Health Care Policy and Research, Olmsted Medical Center, Rochester, MN.
authors.forename: Jeanette Y
authors.initials: JY
authors.lastname: Ziegenfuss
authors.affiliation: Division of Health Care Policy and Research, Olmsted Medical Center, Rochester, MN.
authors.forename: Megan E
authors.initials: ME
authors.lastname: Branda
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Mayo Clinic, Olmsted Medical Center, Rochester, MN.
authors.forename: Kaiser G
authors.initials: KG
authors.lastname: Lim
authors.affiliation: Department of Research, Olmsted Medical Center, Rochester, MN.
authors.forename: Barbara P
authors.initials: BP
authors.lastname: Yawn
authors.affiliation: Division of Health Care Policy and Research, Olmsted Medical Center, Rochester, MN.
authors.forename: Nilay D
authors.initials: ND
authors.lastname: Shah
mesh_terms: D000293:Adolescent; D000305:Adrenal Cortex Hormones / Q000627:therapeutic use*; D000328:Adult; D018927:Anti-Asthmatic Agents / Q000627:therapeutic use*; D001249:Asthma / Q000188:drug therapy / Q000208:ethnology / Q000503:physiopathology* / Q000517:prevention & control; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data; D005260:Female; D019983:Guideline Adherence; D019538:Health Care Surveys; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance; D012720:Severity of Illness Index; D055815:Young Adult
chemical_list: D000305:Adrenal Cortex Hormones; D018927:Anti-Asthmatic Agents