title: Out-of-pocket medication costs and use of medications and health care services among children with asthma.
abstract: BACKGROUND
  Health plans have implemented policies to restrain prescription medication spending by shifting costs toward patients. It is unknown how these policies have affected children with chronic illness.
  
  
  OBJECTIVE
  To analyze the association of medication cost sharing with medication and hospital services utilization among children with asthma, the most prevalent chronic disease of childhood.
  
  
  METHODS
  Retrospective study of insurance claims for 8834 US children with asthma who initiated asthma control therapy between 1997 and 2007. Using variation in out-of-pocket costs for a fixed "basket" of asthma medications across 37 employers, we estimated multivariate models of asthma medication use, asthma-related hospitalization, and emergency department (ED) visits with respect to out-of-pocket costs and child and family characteristics.
  
  
  METHODS
  Asthma medication use, asthma-related hospitalizations, and ED visits during 1-year follow-up.
  
  
  RESULTS
  The mean annual out-of-pocket asthma medication cost was $154 (95% CI, $152-$156) among children aged 5 to 18 years and $151 (95% CI, $148-$153) among those younger than 5 years. Among 5913 children aged 5 to 18 years, filled asthma prescriptions covered a mean of 40.9% of days (95% CI, 40.2%-41.5%). During 1-year follow-up, 121 children (2.1%) had an asthma-related hospitalization and 220 (3.7%) had an ED visit. Among 2921 children younger than 5 years, mean medication use was 46.2% of days (95% CI, 45.2%-47.1%); 136 children (4.7%) had an asthma-related hospitalization and 231 (7.9%) had an ED visit. An increase in out-of-pocket medication costs from the 25th to the 75th percentile was associated with a reduction in adjusted medication use among children aged 5 to 18 years (41.7% [95% CI, 40.7%-42.7%] vs 40.3% [95% CI, 39.4%-41.3%] of days; P = .02) but no change among younger children. Adjusted rates of asthma-related hospitalization were higher for children aged 5 to 18 years in the top quartile of out-of-pocket costs (2.4 [95% CI, 1.9-2.8] hospitalizations per 100 children vs 1.7 [95% CI, 1.3-2.1] per 100 in bottom quartile; P = .004) but not for younger children. Annual adjusted rates of ED use did not vary across out-of-pocket quartiles for either age group.
  
  
  CONCLUSIONS
  Greater cost sharing for asthma medications was associated with a slight reduction in medication use and higher rates of asthma hospitalization among children aged 5 years or older.
authors.affiliation: Division of Health Policy and Management, School of Public Health, University of Minnesota, Minneapolis, USA.
authors.forename: Pinar
authors.initials: P
authors.lastname: Karaca-Mandic
authors.forename: Anupam B
authors.initials: AB
authors.lastname: Jena
authors.forename: Geoffrey F
authors.initials: GF
authors.lastname: Joyce
authors.forename: Dana P
authors.initials: DP
authors.lastname: Goldman
mesh_terms: D000293:Adolescent; D018927:Anti-Asthmatic Agents / Q000191:economics* / Q000627:therapeutic use; D001249:Asthma / Q000191:economics* / Q000628:therapy*; D002648:Child; D002675:Child, Preschool; D017047:Cost Sharing; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D005382:Financing, Personal; D017048:Health Care Costs / Q000706:statistics & numerical data*; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D007345:Insurance Claim Review; D008297:Male; D012189:Retrospective Studies
chemical_list: D018927:Anti-Asthmatic Agents