title: Effects of a prior-authorization policy for celecoxib on medical service and prescription drug use in a managed care Medicaid population.
abstract: BACKGROUND
  Prior authorization (PA) is a poorly studied but commonly employed policy used by health care payers to manage the rising costs of pharmacy benefits.
  
  
  OBJECTIVE
  The aim of this study was to evaluate the intended and unintended effects of a PA policy for celecoxib on pharmacy and medical-service utilization in a Medicaid managed-care organization.
  
  
  METHODS
  This was a retrospective, interrupted time-series analysis of 22 monthly health-related utilization rates from January 1, 1999, to October 31, 2000. All Medicaid claims for CareOregon (a managed-care organization) and a fee-for-service program were reviewed. A model was constructed to evaluate changes in utilization of therapeutically related drug classes (eg, conventional nonsteroidal anti-inflammatory drugs [NSAIDs], gastrointestinal agents), office and emergency-department encounters, and hospitalizations before and after the PA policy was implemented on November 16, 1999. A secondary analysis evaluated these changes among a sample of prior NSAID users.
  
  
  RESULTS
  After the PA policy was implemented, use of celecoxib was immediately reduced from 1.07 to 0.53 days' supply per person-year (58.9%; 95% CI, 50.0%-67.9%). The monthly rate of increase was also reduced (P < 0.001). Utilization changes were not observed in other drug classes. Similar changes were observed in the secondary analysis. An 18% (95% CI, 2.2%-33.9%) nonsignificant increase in emergency-department visits was observed in the entire sample after the PA policy was implemented. However, a similar change was not observed in the secondary analysis of prior NSAID users. No other changes in medical service encounters were noted after the PA policy was activated.
  
  
  CONCLUSIONS
  This observational study found that celecoxib use was substantially reduced after the implementation of a PA policy. No important changes in use of other drug classes were detected. The overall increase in emergency-department visits--although not observed among previous NSAID users--should be explored on the individual level.
authors.affiliation: Oregon State University College of Pharmacy, Portland, USA.
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Hartung
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Touchette
authors.forename: Kathy L
authors.initials: KL
authors.lastname: Ketchum
authors.forename: Dean G
authors.initials: DG
authors.lastname: Haxby
authors.forename: Bruce W
authors.initials: BW
authors.lastname: Goldberg
mesh_terms: D000328:Adult; D000068579:Celecoxib; D051546:Cyclooxygenase 2; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors / Q000191:economics / Q000627:therapeutic use*; D016527:Drug Costs; D011307:Drug Prescriptions; D004363:Drug Utilization; D017850:Economics, Pharmaceutical; D005260:Female; D006801:Humans; D007527:Isoenzymes / Q000037:antagonists & inhibitors*; D008297:Male; D008329:Managed Care Programs / Q000191:economics*; D008484:Medicaid / Q000191:economics*; D008565:Membrane Proteins; D018803:Models, Economic; D011451:Prostaglandin-Endoperoxide Synthases; D011720:Pyrazoles / Q000191:economics / Q000627:therapeutic use*; D012051:Reimbursement Mechanisms / Q000458:organization & administration*; D012189:Retrospective Studies; D013449:Sulfonamides / Q000191:economics / Q000627:therapeutic use*
chemical_list: D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors; D007527:Isoenzymes; D008565:Membrane Proteins; D011720:Pyrazoles; D013449:Sulfonamides; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; D000068579:Celecoxib