title: Association between teriparatide adherence and healthcare utilization and costs in real-world US kyphoplasty/vertebroplasty patients.
abstract: The objective of this study was to examine the association between teriparatide adherence and healthcare utilization and costs in real-world US kyphoplasty/vertebroplasty (KV) patients. Among KV patients newly initiating teriparatide, significantly increased pharmacy costs associated with high teriparatide adherence were offset by significantly lower inpatient utilization and medical costs.
  
  
  BACKGROUND
  This study seeks to examine the association between teriparatide adherence and healthcare utilization/costs in real-world US KV patients.
  
  
  METHODS
  Identified patients from a large US administrative claims database were aged 50+ with KV from 1/1/2002-12/31/2010 (first observed KV = index). Included individuals had 6+ months of pre-index continuous enrollment and no pre-index teriparatide, cancer, or Paget's disease. Follow-up period for patients initiating teriparatide was ≤36 months post-index. Three teriparatide adherence cohorts were constructed using the proportion of days covered (PDC) during the follow-up period: low (PDC ≤ 0.5), medium (PDC >0.5-≤ 0.8), and high (PDC >0.8). Repeated KV admissions, any inpatient admission, number of inpatient admissions, and per-patient-per-month (PPPM) inpatient, outpatient, pharmacy, and total costs were compared between cohorts. The associations between teriparatide adherence and healthcare utilization/costs were examined using multivariable regression models, adjusting for patient demographics and clinical characteristics.
  
  
  RESULTS
  Included were 1,568 patients (mean age, 75 years; 82% female): 403 (26%) had low adherence, 382 (24%) medium, and 783 (50%) high. After multivariable adjustment, high adherence was significantly associated with the lowest PPPM inpatient (low = $1,287; medium = $1,005; high = $678) and outpatient (low = $1,464; medium = $1,244; high = $1,077) medical costs, but with increased pharmacy costs (low = $752; medium = $1,159; high = $1,616; all P < 0.05), leading to similar total costs (low = $3,344; medium = $3,376; high = $3,351) between cohorts; high adherence was also significantly associated with the lowest odds of repeated KV admission, any inpatient admission, and number of inpatient admissions (all P < 0.05).
  
  
  CONCLUSIONS
  Among KV patients initiating teriparatide, significantly increased pharmacy costs associated with high teriparatide adherence were offset by significantly lower inpatient utilization and medical costs.
authors.affiliation: Novartis Pharmaceuticals Corporation, East Hanover, NJ, USA. yzhao00@hotmail.com
authors.forename: Y
authors.initials: Y
authors.lastname: Zhao
authors.forename: S S
authors.initials: SS
authors.lastname: Johnston
authors.forename: D M
authors.initials: DM
authors.lastname: Smith
authors.forename: D
authors.initials: D
authors.lastname: McMorrow
authors.forename: K
authors.initials: K
authors.lastname: Krohn
authors.forename: J
authors.initials: J
authors.lastname: Krege
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D050071:Bone Density Conservation Agents / Q000191:economics / Q000627:therapeutic use*; D003695:Delivery of Health Care / Q000706:statistics & numerical data*; D016527:Drug Costs / Q000706:statistics & numerical data; D005260:Female; D017048:Health Care Costs / Q000706:statistics & numerical data*; D006302:Health Services Research / Q000379:methods; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D058498:Kyphoplasty; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000188:drug therapy / Q000191:economics; D019379:Teriparatide / Q000191:economics / Q000627:therapeutic use*; D014481:United States; D054854:Vertebroplasty; D016903:Drug Monitoring
chemical_list: D050071:Bone Density Conservation Agents; D019379:Teriparatide