title: Prevalence, incidence and persistence of anti-asthma medication use in 2- to 29-year-olds: a nationwide prescription study.
abstract: OBJECTIVE
  The purpose of this study was to examine gender- and age-specific prevalence, incidence, and the type of anti-asthma medications used in the Norwegian population aged 2-29 years during 2005-2007 and to estimate the share of individuals who regularly redeemed medications over a 3-year period.
  
  
  METHODS
  We retrieved data from the nationwide Norwegian Prescription Database for all individuals 2-29 years old (n = 1.7 million) who received anti-asthma medications during 2005-2007. Medications included inhaled short- and long-acting beta(2)-agonists, inhaled corticosteroids, fixed-dose combinations of inhaled beta(2)-agonists and corticosteroids, and leukotriene antagonists.
  
  
  RESULTS
  In 2007, 5.5% (92,074 individuals) of Norwegians aged 2-29 years received anti-asthma medication, and this figure was stable throughout 2005-2007. Prevalence and incidence were higher among males than females but shifted to female dominance during adolescence. The share of anti-asthma medication users who received inhaled corticosteroids was high in preschool children but decreased by age. Conversely, use of inhaled beta(2)-agonists as monotherapy and of fixed combinations increased with age. Fewer than half the individuals were "persistent" to medication treatment for 3 years by redeeming prescriptions regularly (at least once a year).
  
  
  CONCLUSIONS
  In this nationwide study, annual prevalence of anti-asthma medication use was stable during 2005-2007. The gender- and age-specific profile of prevalence and incidence correspond well with other studies. Fewer than half the individuals redeemed prescriptions regularly over 3 years.
authors: Norwegian Institute of Public Health, Oslo, Norway. oystein.karlstad@fhi.no
authors: Oystein
authors: O
authors: Karlstad
authors: Per
authors: P
authors: Nafstad
authors: Aage
authors: A
authors: Tverdal
authors: Svetlana
authors: S
authors: Skurtveit
authors: Kari
authors: K
authors: Furu
mesh_terms: D000293:Adolescent; D000305:Adrenal Cortex Hormones / Q000627:therapeutic use*; D001249:Asthma / Q000188:drug therapy* / Q000453:epidemiology*; D002648:Child; D016208:Databases, Factual; D005260:Female; D006801:Humans; D015994:Incidence; D020024:Leukotriene Antagonists / Q000627:therapeutic use*; D008297:Male; D055656:Prescriptions; D015995:Prevalence
chemical_list: D000305:Adrenal Cortex Hormones; D020024:Leukotriene Antagonists