title: Increasing time costs and copayments for prescription drugs: an analysis of policy changes in a complex environment.
abstract: OBJECTIVE
  To estimate the effect of two separate policy changes in the North Carolina Medicaid program: (1) reduced prescription lengths from 100 to 34 days' supply, and (2) increased copayments for brand name medications.
  
  
  METHODS
  Medicaid claims data were obtained from the Centers for Medicare and Medicaid Services for January 1, 2000-December 31, 2002.
  
  
  METHODS
  We used a pre-post controlled partial difference-in-difference-in-differences design to examine the effect of the policy change on adults in North Carolina; adult Medicaid recipients from Georgia served as controls. Outcomes examined include medication adherence and Medicaid expenditures.
  
  
  METHODS
  Data were aggregated to the person-quarter level. Individuals in HMOs, nursing homes, pregnant, or deceased in the quarter were excluded.
  
  
  RESULTS
  Both policies decreased medication adherence. The days' supply policy had a much larger effect on adherence than did the copayment increase. Total Medicaid spending declined from the days' supply policy, but the copayment policy resulted in a net increase in Medicaid expenditures.
  
  
  CONCLUSIONS
  Although Medicaid costs decreased with the change in days supply policy, these savings were due to reduced adherence to these chronic medications. Additional research should examine the effect of these policy changes from the perspective of Medicaid enrollees.
authors.affiliation: Department of Health Policy and Management, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, 135 Dauer Drive, Chapel Hill, NC 27599-7411, USA.
authors.forename: Marisa Elena
authors.initials: ME
authors.lastname: Domino
authors.forename: Bradley C
authors.initials: BC
authors.lastname: Martin
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Wiley-Exley
authors.forename: Shirley
authors.initials: S
authors.lastname: Richards
authors.forename: Abel
authors.initials: A
authors.lastname: Henson
authors.forename: Timothy S
authors.initials: TS
authors.lastname: Carey
authors.forename: Betsy
authors.initials: B
authors.lastname: Sleath
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D002908:Chronic Disease / Q000188:drug therapy; D003363:Cost Control; D003669:Deductibles and Coinsurance / Q000191:economics*; D005260:Female; D005102:Health Expenditures; D006291:Health Policy / Q000191:economics*; D006801:Humans; D007356:Insurance, Pharmaceutical Services / Q000191:economics*; D016018:Least-Squares Analysis; D008297:Male; D008484:Medicaid / Q000191:economics*; D055118:Medication Adherence; D008875:Middle Aged; D009657:North Carolina; D014481:United States