title: Association between osteoporosis treatment change and adherence, incident fracture, and total healthcare costs in a Medicare Advantage Prescription Drug plan.
abstract: We examined the association between osteoporosis treatment change and adherence, incident fractures, and healthcare costs among Medicare Advantage Prescription Drug (MAPD) plan members. Treatment change was associated with a small but significant increase in adherence, but was not associated with incident fracture or total healthcare costs. Overall adherence remained low.
  
  
  BACKGROUND
  We examined the association between osteoporosis treatment change and adherence, incident fractures, and healthcare costs among MAPD plan members in a large US health plan.
  
  
  METHODS
  We conducted a retrospective cohort study of MAPD plan members aged≥50 years newly initiated on an osteoporosis medication between 1 January 2006 and 31 December 2008. Members were identified as having or not having an osteoporosis treatment change within 12 months after initiating osteoporosis medication. Logistic regression analyses and difference-in-difference (DID) generalized linear models were used to investigate the association between osteoporosis treatment change and (1) adherence to treatment, (2) incident fracture, and (3) healthcare costs at 12 and 24 months follow-up.
  
  
  RESULTS
  Of the 33,823 members newly initiated on osteoporosis treatment, 3,573 (10.6%) changed osteoporosis treatment within 12 months. After controlling for covariates, osteoporosis treatment change was associated with significantly higher odds of being adherent (medication possession ratio [MPR]≥0.8) at 12 months (odds ratio [OR]=1.18) and 24 months (OR=1.13) follow-up. However, overall adherence remained low (MPR=0.59 and 0.51 for the change cohort and MPR=0.51 and 0.44 for the no-change cohort at 12 and 24 months, respectively). Osteoporosis treatment change was not significantly associated with incident fracture (OR=1.00 at 12 months and OR=0.98 at 24 months) or total direct healthcare costs (p>0.4) in the DID analysis, but was associated with higher pharmacy costs (p<0.004).
  
  
  CONCLUSIONS
  Osteoporosis treatment change was associated with a small but significant increase in adherence, but was not associated with incident fracture or total healthcare costs in the MAPD plan population. Overall adherence to therapy remained low.
authors.affiliation: Competitive Health Analytics, Inc., 321 West Main Street, WFP6W, Louisville, KY 40202, USA. mward@humana.com
authors.forename: M A
authors.initials: MA
authors.lastname: Ward
authors.forename: Y
authors.initials: Y
authors.lastname: Xu
authors.forename: H N
authors.initials: HN
authors.lastname: Viswanathan
authors.forename: B S
authors.initials: BS
authors.lastname: Stolshek
authors.forename: B
authors.initials: B
authors.lastname: Clay
authors.forename: J L
authors.initials: JL
authors.lastname: Adams
authors.forename: J D
authors.initials: JD
authors.lastname: Kallich
authors.forename: S
authors.initials: S
authors.lastname: Fine
authors.forename: K G
authors.initials: KG
authors.lastname: Saag
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D050071:Bone Density Conservation Agents / Q000191:economics / Q000627:therapeutic use*; D016527:Drug Costs / Q000706:statistics & numerical data; D057915:Drug Substitution / Q000191:economics / Q000706:statistics & numerical data; D005260:Female; D005500:Follow-Up Studies; D017048:Health Care Costs / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D008297:Male; D020398:Medicare Part C / Q000191:economics; D008875:Middle Aged; D010024:Osteoporosis / Q000188:drug therapy* / Q000191:economics / Q000453:epidemiology; D058866:Osteoporotic Fractures / Q000191:economics / Q000453:epidemiology / Q000517:prevention & control*; D014481:United States / Q000453:epidemiology; D016903:Drug Monitoring
chemical_list: D050071:Bone Density Conservation Agents