title: Preferred drug lists and Medicaid prescriptions.
abstract: BACKGROUND
  When Medicaid preferred drug lists (PDLs) are implemented, they may impose indirect costs on prescribing physicians and Medicaid patients, leading to an unintended reduction in the number of Medicaid prescriptions filled.
  
  
  OBJECTIVE
  To test retrospectively the proposition that PDLs adversely affect the number of Medicaid prescriptions filled.
  
  
  METHODS
  We compared three 'test' states (Alabama, Texas, and Virginia) that implemented PDLs with restrictions on the prescription of statins with three 'control' states (New Jersey, North Carolina, and Pennsylvania) that did not implement drug access restrictions. We conducted the analysis at the county level and used a differences-in-differences approach that allows for county and time-period fixed effects.
  
  
  RESULTS
  We found that PDLs adversely impacted several measures of filled Medicaid prescriptions in the 'test' states relative to the 'control' states.
  
  
  CONCLUSIONS
  There are unintended but potentially harmful consequences to cost-focused health policy interventions.
authors.affiliation: Pfizer Inc, New York, NY 10017, USA. tamer.abdelgawad@pfizer.com
authors.forename: Tamer
authors.initials: T
authors.lastname: Abdelgawad
authors.forename: Lisa
authors.initials: L
authors.lastname: Egbuonu-Davis
mesh_terms: D016527:Drug Costs; D011307:Drug Prescriptions / Q000191:economics*; D017850:Economics, Pharmaceutical / Q000706:statistics & numerical data / Q000639:trends; D005569:Formularies as Topic; D006801:Humans; D008484:Medicaid / Q000191:economics* / Q000331:legislation & jurisprudence / Q000639:trends; D004364:Pharmaceutical Preparations / Q000191:economics*; D012189:Retrospective Studies; D013781:Texas; D014768:Virginia
chemical_list: D004364:Pharmaceutical Preparations