title: The effect of a copay increase on pharmaceutical utilization, expenditures, and treatment continuation.
abstract: OBJECTIVE
  No research has evaluated the impact of an increase to a copay that is reflective of today's healthcare market. This study examined the effect of an increase from a $10 to $15 copay for brand drugs on key pharmaceutical utilization measures, including participation rates, treatment continuation, and expenditures, in an adult population.
  
  
  METHODS
  A quasi-experimental, pre-post design with control group was used.
  
  
  METHODS
  Two different employer plans implemented an increase from $10 to $15 for brand copays in January of 1997. The utilization and expenditures of these plans were compared with those of a control group with a constant brand copay of $10 for 6 months preceding and 6 months following the copay increase.
  
  
  RESULTS
  When other predictor variables were controlled for, the copay increase was not associated with a statistically significant difference in overall utilization compared with the control group, although brand utilization was significantly lower in the copay group. Savings to the payer were substantial, and resulted primarily from cost-shifting, reduction in brand utilization, and an increase in the generic fill rate. The rates of continuation with chronic medications in the 6 months following the copay increase were not reduced in the copay group compared with the control group.
  
  
  CONCLUSIONS
  A copay increase can provide substantial savings to a payer without being a major deterrent to overall utilization or resulting in discontinuation of chronic medications.
authors.affiliation: University of Arizona College of Pharmacy, Tucson, AZ, USA. Motheral@pharmacy.arizona.edu
authors.forename: B R
authors.initials: BR
authors.lastname: Motheral
authors.forename: R
authors.initials: R
authors.lastname: Henderson
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D015984:Causality; D002908:Chronic Disease / Q000188:drug therapy; D003361:Cost Allocation; D017046:Cost Savings; D017047:Cost Sharing / Q000706:statistics & numerical data*; D004363:Drug Utilization / Q000191:economics* / Q000706:statistics & numerical data; D016568:Drugs, Generic / Q000191:economics* / Q000627:therapeutic use*; D005252:Fees, Pharmaceutical / Q000706:statistics & numerical data*; D005260:Female; D006264:Health Benefit Plans, Employee / Q000191:economics* / Q000706:statistics & numerical data; D005102:Health Expenditures / Q000706:statistics & numerical data* / Q000639:trends; D006302:Health Services Research / Q000379:methods; D006801:Humans; D016015:Logistic Models; D008329:Managed Care Programs / Q000191:economics; D008875:Middle Aged; D015999:Multivariate Analysis; D010349:Patient Compliance; D014481:United States
chemical_list: D016568:Drugs, Generic