title: Association of authorized generic marketing with prescription drug spending on antidepressants from 2000 to 2011.
abstract: OBJECTIVE
  Prior research suggests that authorized generic drugs increase competition and decrease prices, but little empirical evidence supports this conclusion. This study evaluated the impact of authorized generic marketing on brand and generic prices.
  
  
  METHODS
  Longitudinal analysis of the household component of the Medical Expenditure Panel Survey.
  
  
  METHODS
  Interview panels over 12 years, with a new panel each year. For each panel, 5 rounds of household interviews were conducted over 30 months.
  
  
  METHODS
  Nationally representative sample of the U.S. civilian noninstitutionalized population, focusing on people using 1 of 5 antidepressant drugs that became generically available between 2000 to 2011.
  
  
  METHODS
  Drugs and dose/formulations with versus without an authorized generic drug marketed.
  
  
  METHODS
  Multiple linear regression models with lagged variables evaluated the effect of an authorized generic on average inflation-adjusted brand and generic price, adjusting for payment sources, generic entry time, competitor price, and year.
  
  
  RESULTS
  During 2000-2011, annual brand antidepressant utilization decreased from 51.47 to 7.52 million prescriptions, and generic antidepressant utilization increased from 0 to 88.83 million prescriptions. Over time, payment per prescription for brand prescriptions increased 25% overall, and generic payments decreased 70% for all payer types. With unadjusted data, after generic entry the average brand price decreased $0.59 per year with and $3.62 per year without an authorized generic in the market. Average generic prices decreased $10.30 per year with and $8.47 per year without an authorized generic in the market. In multiple regression models with lagged variables adjusted for heteroscedasticity, payer source, time since generic entry, competitor price, and year, authorized generics significantly reduced average payment for generic (-$3.03) and brand (-$60.64) prescriptions, and over time this price change slowly diminished.
  
  
  CONCLUSIONS
  Availability of an authorized generic was associated with reduced average generic and brand price in the antidepressant market, supporting prior evidences.
authors.forename: Ning
authors.initials: N
authors.lastname: Cheng
authors.forename: Tannista
authors.initials: T
authors.lastname: Banerjee
authors.forename: Jingjing
authors.initials: J
authors.lastname: Qian
authors.forename: Richard A
authors.initials: RA
authors.lastname: Hansen
mesh_terms: D000928:Antidepressive Agents / Q000191:economics* / Q000627:therapeutic use; D003430:Cross-Sectional Studies; D016527:Drug Costs / Q000706:statistics & numerical data; D004345:Drug Industry / Q000191:economics; D011307:Drug Prescriptions / Q000191:economics; D016568:Drugs, Generic / Q000191:economics* / Q000627:therapeutic use; D005102:Health Expenditures / Q000706:statistics & numerical data; D006801:Humans; D008137:Longitudinal Studies; D040541:Marketing / Q000191:economics*; D055553:Prescription Drugs / Q000191:economics* / Q000627:therapeutic use; D011795:Surveys and Questionnaires; D014481:United States
chemical_list: D000928:Antidepressive Agents; D016568:Drugs, Generic; D055553:Prescription Drugs