title: Health care system-level factors associated with performance on Medicare STAR adherence metrics in a large, integrated delivery system.
abstract: BACKGROUND
  The Centers for Medicare and Medicaid Services provide significant incentives to health plans that score well on Medicare STAR metrics for cardiovascular disease risk factor medication adherence. Information on modifiable health system-level predictors of adherence can help clinicians and health plans develop strategies for improving Medicare STAR scores, and potentially improve cardiovascular disease outcomes.
  
  
  OBJECTIVE
  To examine the association of Medicare STAR adherence metrics with system-level factors.
  
  
  METHODS
  A cross-sectional study.
  
  
  METHODS
  A total of 129,040 diabetes patients aged 65 years and above in 2010 from 3 Kaiser Permanente regions.
  
  
  METHODS
  Adherence to antihypertensive, antihyperlipidemic, and oral antihyperglycemic medications in 2010, defined by Medicare STAR as the proportion of days covered ≥ 80%.
  
  
  RESULTS
  After controlling for individual-level factors, the strongest predictor of achieving STAR-defined medication adherence was a mean prescribed medication days' supply of > 90 days (RR=1.61 for antihypertensives, oral antihyperglycemics, and statins; all P < 0.001). Using mail order pharmacy to fill medications > 50% of the time was independently associated with better adherence with these medications (RR = 1.07, 1.06, 1.07; P < 0.001); mail order use had an increased positive association among black and Hispanic patients. Medication copayments ≤ $10 for 30 days' supply (RR = 1.02, 1.02, 1.02; P < 0.01) and annual individual out-of-pocket maximums ≤ $2000 (RR = 1.02, 1.01, 1.02; P < 0.01) were also significantly associated with higher adherence for all 3 therapeutic groupings.
  
  
  CONCLUSIONS
  Greater medication days' supply and mail order pharmacy use, and lower copayments and out-of-pocket maximums, are associated with better Medicare STAR adherence. Initiatives to improve adherence should focus on modifiable health system-level barriers to obtaining evidence-based medications.
authors.affiliation: *Division of Research, Kaiser Permanente Northern California, Oakland, CA †Center for Health Research, Kaiser Permanente Northwest, Portland, OR ‡Institute for Health Research, Kaiser Permanente Colorado, Denver, CO.
authors.forename: Julie A
authors.initials: JA
authors.lastname: Schmittdiel
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Nichols
authors.forename: Wendy
authors.initials: W
authors.lastname: Dyer
authors.forename: John F
authors.initials: JF
authors.lastname: Steiner
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Karter
authors.forename: Marsha A
authors.initials: MA
authors.lastname: Raebel
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000959:Antihypertensive Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D017047:Cost Sharing / Q000706:statistics & numerical data; D003430:Cross-Sectional Studies; D003920:Diabetes Mellitus / Q000188:drug therapy*; D004363:Drug Utilization; D005260:Female; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000008:administration & dosage* / Q000627:therapeutic use; D007004:Hypoglycemic Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D007345:Insurance Claim Review / Q000706:statistics & numerical data; D008297:Male; D006278:Medicare / Q000706:statistics & numerical data*; D011177:Postal Service / Q000706:statistics & numerical data; D012959:Socioeconomic Factors; D014481:United States; D016903:Drug Monitoring
chemical_list: D000959:Antihypertensive Agents; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D007004:Hypoglycemic Agents