title: Analysis of osteoporosis treatment patterns with bisphosphonates and outcomes among postmenopausal veterans.
abstract: OBJECTIVE
  Adherence and persistence with bisphosphonates are frequently poor, and stopping, restarting, or switching bisphosphonates is common. We evaluated bisphosphonate change behaviors (switching, discontinuing, or reinitiating) over time, as well as fractures and costs, among a large, national cohort of postmenopausal veterans.
  
  
  METHODS
  Female veterans aged 50+ treated with bisphosphonates during 2003-2011 were identified in Veterans Health Administration (VHA) datasets. Bisphosphonate change behaviors were characterized using pharmacy refill records. Patients' baseline disease severity was characterized based on age, T-score, and prior fracture. Cox Proportional Hazard analysis was used to evaluate characteristics associated with discontinuation and the relationship between change behaviors and fracture outcomes. Generalized estimating equations were used to evaluate the relationship between change behaviors and cost outcomes.
  
  
  RESULTS
  A total of 35,650 patients met eligibility criteria. Over 6800 patients (19.1%) were non-switchers. The remaining patients were in the change cohort; at least half displayed more than one change behavior over time. A strong, significant predictor of discontinuation was ≥5 healthcare visits in the prior year (11-23% more likely to discontinue), and discontinuation risk decreased with increasing age. No change behaviors were associated with increased fracture risk. Total costs were significantly higher in patients with change behaviors (4.7-19.7% higher). Change-behavior patients mostly had significantly lower osteoporosis-related costs than non-switchers (22%-118% lower).
  
  
  CONCLUSIONS
  Most bisphosphonate patients discontinue treatment at some point, which did not significantly increase the risk of fracture in this majority non-high risk population. Bisphosphonate change behaviors were associated with significantly lower osteoporosis costs, but significantly higher total costs.
authors.affiliation: Pharmacotherapy Outcomes Research Center, University of Utah, 30 South 2000 East, Salt Lake City, UT 84112, USA; VA Salt Lake City Heath Care System, 500 Foothill Drive, Salt Lake City, UT 84148, USA. Electronic address: joanne.lafleur@pharm.utah.edu.
authors.forename: J
authors.initials: J
authors.lastname: LaFleur
authors.affiliation: Pharmacotherapy Outcomes Research Center, University of Utah, 30 South 2000 East, Salt Lake City, UT 84112, USA; VA Salt Lake City Heath Care System, 500 Foothill Drive, Salt Lake City, UT 84148, USA.
authors.forename: S L
authors.initials: SL
authors.lastname: DuVall
authors.affiliation: Pharmacotherapy Outcomes Research Center, University of Utah, 30 South 2000 East, Salt Lake City, UT 84112, USA; VA Salt Lake City Heath Care System, 500 Foothill Drive, Salt Lake City, UT 84148, USA.
authors.forename: T
authors.initials: T
authors.lastname: Willson
authors.affiliation: VA Salt Lake City Heath Care System, 500 Foothill Drive, Salt Lake City, UT 84148, USA.
authors.forename: T
authors.initials: T
authors.lastname: Ginter
authors.affiliation: VA Salt Lake City Heath Care System, 500 Foothill Drive, Salt Lake City, UT 84148, USA.
authors.forename: O
authors.initials: O
authors.lastname: Patterson
authors.affiliation: Pharmacotherapy Outcomes Research Center, University of Utah, 30 South 2000 East, Salt Lake City, UT 84112, USA; VA Salt Lake City Heath Care System, 500 Foothill Drive, Salt Lake City, UT 84148, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Cheng
authors.affiliation: Pharmacotherapy Outcomes Research Center, University of Utah, 30 South 2000 East, Salt Lake City, UT 84112, USA.
authors.forename: K
authors.initials: K
authors.lastname: Knippenberg
authors.affiliation: VA Salt Lake City Heath Care System, 500 Foothill Drive, Salt Lake City, UT 84148, USA; Department of Internal Medicine, University of Utah, 30 North 1900 East, Salt Lake City, UT 84132, USA.
authors.forename: C
authors.initials: C
authors.lastname: Haroldsen
authors.affiliation: Hunter Holmes McGuire Veterans Affairs Medical Center, 1201 Broad Rock Boulevard, Richmond, VA 23224, USA.
authors.forename: R A
authors.initials: RA
authors.lastname: Adler
authors.affiliation: Division of Clinical Immunology and Rheumatology, University of Alabama at Birmingham, 1825 University Boulevard, Birmingham, AL 35294-2182, USA.
authors.forename: J R
authors.initials: JR
authors.lastname: Curtis
authors.affiliation: Amgen, Inc., 1 Amgen Center Drive, Thousand Oaks, CA 91320, USA.
authors.forename: I
authors.initials: I
authors.lastname: Agodoa
authors.affiliation: VA Salt Lake City Heath Care System, 500 Foothill Drive, Salt Lake City, UT 84148, USA; Department of Internal Medicine, University of Utah, 30 North 1900 East, Salt Lake City, UT 84132, USA.
authors.forename: R E
authors.initials: RE
authors.lastname: Nelson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D050071:Bone Density Conservation Agents / Q000627:therapeutic use; D015331:Cohort Studies; D004164:Diphosphonates / Q000627:therapeutic use*; D005260:Female; D006787:Hospitals, Veterans; D006801:Humans; D055118:Medication Adherence; D008875:Middle Aged; D009323:Natural Language Processing; D015663:Osteoporosis, Postmenopausal / Q000188:drug therapy*; D058866:Osteoporotic Fractures / Q000188:drug therapy / Q000517:prevention & control; D063868:Patient Outcome Assessment; D016016:Proportional Hazards Models; D014481:United States; D014728:Veterans
chemical_list: D050071:Bone Density Conservation Agents; D004164:Diphosphonates
keywords: Bisphosphonate; Cost; Fracture risk; Osteoporosis; Treatment patterns; Veterans