title: Compliance with osteoporosis drug therapy and risk of fracture.
abstract: BACKGROUND
  Patient compliance with osteoporosis drug therapy is often poor in clinical practice and may be associated with higher risk of fracture.
  
  
  METHODS
  A nested case-control study was undertaken using a US health insurance claims database. The source population included all women aged >or=45 years who began drug therapy for osteoporosis. Cases consisted of those who experienced an osteoporosis-related fracture; they were matched to controls without osteoporosis-related fracture. Compliance with osteoporosis drug treatment was assessed in terms of the number of therapy-days received and medication possession ratio (MPR). Conditional logistic regression was employed to examine the relationship between compliance and fracture risk.
  
  
  RESULTS
  A total of 453 women with osteoporosis-related fracture were identified and matched to 2,160 controls. Fracture risk was significantly lower for patients with >180 days of therapy [181-360 days: odds ratio (OR) = 0.70, 95% CI = 0.49-0.99; >360 days: OR = 0.65, 95% CI = 0.43-0.99) versus those with <or=30 days. Risk was also lower for patients with MPR >or=90% (OR = 0.70, 95% CI = 0.52-0.93) versus those with MPR <30%. Fracture risk decreased as compliance increased (p(trend) < 0.05).
  
  
  CONCLUSIONS
  Among women initiating drug therapy for osteoporosis, better compliance is associated with reduced risk of fracture.
authors.affiliation: Policy Analysis Inc. (PAI), Four Davis Court, Brookline, MA 02445, USA. dweycker@pai2.com
authors.forename: D
authors.initials: D
authors.lastname: Weycker
authors.forename: D
authors.initials: D
authors.lastname: Macarios
authors.forename: J
authors.initials: J
authors.lastname: Edelsberg
authors.forename: G
authors.initials: G
authors.lastname: Oster
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D050071:Bone Density Conservation Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D004334:Drug Administration Schedule; D004812:Epidemiologic Methods; D005260:Female; D050723:Fractures, Bone / Q000209:etiology / Q000517:prevention & control*; D006801:Humans; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000150:complications / Q000188:drug therapy*; D010349:Patient Compliance / Q000706:statistics & numerical data*
chemical_list: D050071:Bone Density Conservation Agents