title: Falling into the coverage gap: Part D drug costs and adherence for Medicare Advantage prescription drug plan beneficiaries with diabetes.
abstract: OBJECTIVE
  To compare drug costs and adherence among Medicare beneficiaries with the standard Part D coverage gap versus supplemental gap coverage in 2006.
  
  
  METHODS
  Pharmacy data from Medicare Advantage Prescription Drug (MAPD) plans.
  
  
  METHODS
  Parallel analyses comparing beneficiaries aged 65+ with diabetes in an integrated MAPD with a gap versus no gap (n=28,780); and in a network-model MAPD with a gap versus generic-only coverage during the gap (n=14,984).
  
  
  RESULTS
  Drug spending was 3 percent (95 percent confidence interval [CI]: 1-4 percent) and 4 percent (CI: 1-6 percent) lower among beneficiaries with a gap versus full or generic-only gap coverage, respectively. Out-of-pocket expenditures were 189 percent higher (CI: 185-193 percent) and adherence to three chronic drug classes was lower among those with a gap versus no gap (e.g., odds ratio=0.83, CI: 0.79-0.88, for oral diabetes drugs). Annual out-of-pocket spending was 14 percent higher (CI: 10-17 percent) for beneficiaries with a gap versus generic-only gap coverage, but levels of adherence were similar.
  
  
  CONCLUSIONS
  Among Medicare beneficiaries with diabetes, having the Part D coverage gap resulted in lower total drug costs, but higher out-of-pocket spending and worse adherence compared with having no gap. Having generic-only coverage during the gap appeared to confer limited benefits compared with having no gap coverage.
authors.affiliation: Division of Research, Kaiser Permanente Medical Care Program, 2000 Broadway, 3rd floor, Oakland, CA 94612, USA. Vicki.Fung@kp.org
authors.forename: Vicki
authors.initials: V
authors.lastname: Fung
authors.forename: Carol M
authors.initials: CM
authors.lastname: Mangione
authors.forename: Jie
authors.initials: J
authors.lastname: Huang
authors.forename: Norman
authors.initials: N
authors.lastname: Turk
authors.forename: Elaine S
authors.initials: ES
authors.lastname: Quiter
authors.forename: Julie A
authors.initials: JA
authors.lastname: Schmittdiel
authors.forename: John
authors.initials: J
authors.lastname: Hsu
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003920:Diabetes Mellitus / Q000188:drug therapy*; D005252:Fees, Pharmaceutical / Q000639:trends*; D005260:Female; D005382:Financing, Personal; D006801:Humans; D019458:Insurance Coverage / Q000191:economics / Q000331:legislation & jurisprudence* / Q000458:organization & administration; D017054:Insurance, Medigap / Q000191:economics; D008297:Male; D054524:Medicare Part D / Q000191:economics / Q000331:legislation & jurisprudence / Q000458:organization & administration*; D012051:Reimbursement Mechanisms / Q000191:economics / Q000331:legislation & jurisprudence / Q000458:organization & administration*; D014481:United States