title: Patterns of prescription drug expenditures and medication adherence among medicare part D beneficiaries with and without the low-income supplement.
abstract: BACKGROUND
  The association between the Medicare Part D low-income subsidy (LIS), gap coverage, and outcomes such as medical expenditures, prescription fills, and medication adherence is not well understood. The purpose of this study was to examine the relationship between the LIS and these measures for patients within a large, national Part D plan in the United States.
  
  
  METHODS
  In this cross-sectional, retrospective analysis, we compared total and plan expenditures, out-of-pocket costs, and medication fills and adherence for three categories of Medicare beneficiaries: non-LIS beneficiaries without gap coverage (non-LIS/non-GC), non-LIS beneficiaries with gap coverage (non-LIS/GC), and LIS beneficiaries (LIS).
  
  
  RESULTS
  LIS beneficiaries, relative to non-LIS/non-GC and non-LIS/GC beneficiaries, had higher total expenditures ($1,887 vs. $1,360 vs. $1,341); lower out-of-pocket costs ($148 vs. $546 vs. $570); more expenditures exceeding the gap threshold (27.6% vs. 18.4% vs. 16.9%); and slightly higher adherence to blood pressure (65.6% vs. 64.2% vs. 62.4%); diabetes (62.5% vs. 57.7 vs. 57.4%); and lipid-lowering (59.6% vs. 57.0 vs. 55.6%) medications.
  
  
  CONCLUSIONS
  LIS beneficiaries had higher total expenditures, lower out-of-pocket costs, and modestly better adherence to diabetes medications than non-LIS/non-GC and non-LIS/GC beneficiaries.
authors.affiliation: David Geffen School of Medicine at University of California, Los Angeles and Department of Medicine, Division of Cardiology, University of California, Los Angeles 10833 Le Conte Avenue A2-237 Center for the Health Sciences, Los Angeles, CA, 90024, USA. syala@mednet.ucla.edu.|David Geffen School of Medicine at University of California, Los Angeles, Department of Medicine, Division of General Internal Medicine & Health Services Research, 10940 Wilshire Boulevard, Suite 700, Los Angeles, CA, 90024, USA. syala@mednet.ucla.edu.
authors.forename: Stella M
authors.initials: SM
authors.lastname: Yala
authors.affiliation: David Geffen School of Medicine at University of California, Los Angeles and Department of Medicine, Division of Cardiology, University of California, Los Angeles 10833 Le Conte Avenue A2-237 Center for the Health Sciences, Los Angeles, CA, 90024, USA. KDuru@mednet.ucla.edu.|David Geffen School of Medicine at University of California, Los Angeles, Department of Medicine, Division of General Internal Medicine & Health Services Research, 10940 Wilshire Boulevard, Suite 700, Los Angeles, CA, 90024, USA. KDuru@mednet.ucla.edu.
authors.forename: Obidiugwu Kenrik
authors.initials: OK
authors.lastname: Duru
authors.affiliation: David Geffen School of Medicine at University of California, Los Angeles and Department of Medicine, Division of Cardiology, University of California, Los Angeles 10833 Le Conte Avenue A2-237 Center for the Health Sciences, Los Angeles, CA, 90024, USA. settner@mednet.ucla.edu.|David Geffen School of Medicine at University of California, Los Angeles, Department of Medicine, Division of General Internal Medicine & Health Services Research, 10940 Wilshire Boulevard, Suite 700, Los Angeles, CA, 90024, USA. settner@mednet.ucla.edu.|Jonathan Fielding School of Public Health, University of California, Los Angeles 911 Broxton Plaza, Los Angeles, CA, 90024, USA. settner@mednet.ucla.edu.
authors.forename: Susan L
authors.initials: SL
authors.lastname: Ettner
authors.affiliation: David Geffen School of Medicine at University of California, Los Angeles and Department of Medicine, Division of Cardiology, University of California, Los Angeles 10833 Le Conte Avenue A2-237 Center for the Health Sciences, Los Angeles, CA, 90024, USA. NTurk@mednet.ucla.edu.|David Geffen School of Medicine at University of California, Los Angeles, Department of Medicine, Division of General Internal Medicine & Health Services Research, 10940 Wilshire Boulevard, Suite 700, Los Angeles, CA, 90024, USA. NTurk@mednet.ucla.edu.
authors.forename: Norman
authors.initials: N
authors.lastname: Turk
authors.affiliation: David Geffen School of Medicine at University of California, Los Angeles and Department of Medicine, Division of Cardiology, University of California, Los Angeles 10833 Le Conte Avenue A2-237 Center for the Health Sciences, Los Angeles, CA, 90024, USA. CMangione@mednet.ucla.edu.|David Geffen School of Medicine at University of California, Los Angeles, Department of Medicine, Division of General Internal Medicine & Health Services Research, 10940 Wilshire Boulevard, Suite 700, Los Angeles, CA, 90024, USA. CMangione@mednet.ucla.edu.|Jonathan Fielding School of Public Health, University of California, Los Angeles 911 Broxton Plaza, Los Angeles, CA, 90024, USA. CMangione@mednet.ucla.edu.
authors.forename: Carol M
authors.initials: CM
authors.lastname: Mangione
authors.affiliation: David Geffen School of Medicine at University of California, Los Angeles and Department of Medicine, Division of Cardiology, University of California, Los Angeles 10833 Le Conte Avenue A2-237 Center for the Health Sciences, Los Angeles, CA, 90024, USA. abrown@mednet.ucla.edu.|David Geffen School of Medicine at University of California, Los Angeles, Department of Medicine, Division of General Internal Medicine & Health Services Research, 10940 Wilshire Boulevard, Suite 700, Los Angeles, CA, 90024, USA. abrown@mednet.ucla.edu.
authors.forename: Arleen F
authors.initials: AF
authors.lastname: Brown
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D003920:Diabetes Mellitus / Q000188:drug therapy; D005260:Female; D005382:Financing, Personal / Q000191:economics*; D005102:Health Expenditures; D006801:Humans; D019458:Insurance Coverage / Q000191:economics*; D008297:Male; D054524:Medicare Part D / Q000191:economics*; D055118:Medication Adherence; D011203:Poverty; D055553:Prescription Drugs / Q000191:economics*; D012189:Retrospective Studies; D014481:United States
chemical_list: D055553:Prescription Drugs