title: Impact of a step-therapy protocol for pregabalin on healthcare utilization and expenditures in a commercial population.
abstract: OBJECTIVE
  To compare changes in healthcare resource utilization and costs among members with painful diabetic peripheral neuropathy (pDPN), postherpetic neuralgia (PHN), or fibromyalgia (FM) in a commercial health plan implementing pregabalin step-therapy with members in unrestricted plans.
  
  
  METHODS
  Retrospective study of outcomes associated with implementation of a pregabalin step-therapy protocol using claims data from Humana ('restricted' cohort) and Thomson Reuters MarketScan ('unrestricted' cohort). Members aged 18-65 years receiving treatment for pDPN, PHN, or FM during 2008 or 2009 were identified; cohorts were matched on diagnosis and geographic region. Baseline to follow-up changes in healthcare resource utilization and costs were determined using difference-in-differences (DID) analysis. Statistical models adjusting for covariates explored relationships between restricted access and outcomes.
  
  
  RESULTS
  A total of 3876 restricted cohort members were identified and matched to 3876 unrestricted cohort members. FM was the predominant diagnosis (84.7%). The unrestricted cohort was older (mean = 49.0 (SD = 10.4) years vs 47.6 (SD = 10.5) years; p < 0.001), and had greater comorbidity (RxRisk-V score = 5.4 (SD = 3.2) vs 4.4 (SD = 2.9), p < 0.001) than the restricted cohort. Compared with the unrestricted cohort, the restricted cohort demonstrated a greater year-over-year decrease in pregabalin utilization (-2.6%, p = 0.008), and greater increases in physical therapy and disease-related outpatient utilization (3.7%, p = 0.010 and 3.6%, p = 0.022, respectively). There were no statistically significant net differences in all-cause or disease-related total healthcare, medical, or pharmacy costs between cohorts. After adjusting for baseline compositional differences between cohorts, restricted plan membership was associated with a net increase in all-cause medical ($1222; p = 0.016) and disease-related healthcare costs ($859; p = 0.002). Limitations include use of a combined analysis for pDPN, PHN, and FM, especially since the observed results were likely driven by FM; an inability to link the prescribing of a medication with the condition of interest, which is common to claims analyses; and lack of pain severity information.
  
  
  CONCLUSIONS
  Implementation of a pregabalin step-therapy protocol resulted in lower pregabalin utilization, but this restriction was not associated with reductions in total healthcare costs, medical costs, or pharmacy costs.
authors.affiliation: Pfizer Inc, New York, NY, USA.
authors.forename: Margarita
authors.initials: M
authors.lastname: Udall
authors.forename: Anthony
authors.initials: A
authors.lastname: Louder
authors.forename: Brandon T
authors.initials: BT
authors.lastname: Suehs
authors.forename: Joseph C
authors.initials: JC
authors.lastname: Cappelleri
authors.forename: Ashish V
authors.initials: AV
authors.lastname: Joshi
authors.forename: Nick C
authors.initials: NC
authors.lastname: Patel
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000700:Analgesics / Q000191:economics* / Q000627:therapeutic use; D003363:Cost Control; D016208:Databases, Factual; D003929:Diabetic Neuropathies / Q000188:drug therapy*; D005260:Female; D005356:Fibromyalgia / Q000188:drug therapy*; D020793:Gatekeeping / Q000191:economics*; D005102:Health Expenditures; D006801:Humans; D007356:Insurance, Pharmaceutical Services / Q000191:economics; D008297:Male; D008875:Middle Aged; D051474:Neuralgia, Postherpetic / Q000188:drug therapy*; D010593:Pharmaceutical Services / Q000191:economics* / Q000706:statistics & numerical data; D000069583:Pregabalin; D012189:Retrospective Studies; D055815:Young Adult; D005680:gamma-Aminobutyric Acid / Q000031:analogs & derivatives* / Q000191:economics / Q000627:therapeutic use
chemical_list: D000700:Analgesics; D000069583:Pregabalin; D005680:gamma-Aminobutyric Acid