title: Fractures in women treated with raloxifene or alendronate: a retrospective database analysis.
abstract: BACKGROUND
  Raloxifene and alendronate are anti-resorptive therapies approved for the prevention and treatment of postmenopausal osteoporosis. Raloxifene is also indicated to reduce the risk of invasive breast cancer in postmenopausal women with osteoporosis and in postmenopausal women at high risk of invasive breast cancer. A definitive study comparing the fracture effectiveness and rate of breast cancer for raloxifene and alendronate has not been published. The purpose of this retrospective cohort study was to evaluate fracture and breast cancer rates among patients treated with raloxifene or alendronate.
  
  
  METHODS
  Females ≥45 years who initiated raloxifene or alendronate in 1998-2006 Truven Health Analytics MarketScan® Databases, had continuous enrollment 12 months prior to and at least 12 months after the index date, and had a treatment medication possession ratio ≥80% were included in this study. Rates of vertebral and nonvertebral fractures and breast cancer during 1, 3, 5, 6, 7, and 8 years of treatment with raloxifene or alendronate were evaluated. Fracture rates were adjusted for potential treatment bias using inverse probability of treatment weights. Multivariate hazard ratios were estimated for vertebral and nonvertebral fractures.
  
  
  RESULTS
  Raloxifene patients had statistically significantly lower rates of vertebral fractures in 1, 3, 5, and 7 years and for nonvertebral fractures in 1 and 5 years. There were no statistically significant differences in the adjusted fracture rates between raloxifene and alendronate cohorts, except in the 3-year nonvertebral fracture rates where raloxifene was higher. Multivariate hazard ratios of raloxifene versus alendronate cohorts were not significantly different for vertebral and nonvertebral fracture in 1, 3, 5, 6, 7, and 8 years. Unweighted and weighted breast cancer rates were lower among raloxifene recipients.
  
  
  CONCLUSIONS
  Patients treated with alendronate and raloxifene had similar adjusted fracture rates in up to 8 years of adherent treatment, and raloxifene patients had lower breast cancer rates.
authors.affiliation: Eli Lilly and Company, Indianapolis, IN, USA. fostersa@lilly.com
authors.forename: Shonda A
authors.initials: SA
authors.lastname: Foster
authors.forename: Nianwen
authors.initials: N
authors.lastname: Shi
authors.forename: Suellen
authors.initials: S
authors.lastname: Curkendall
authors.forename: John
authors.initials: J
authors.lastname: Stock
authors.forename: Bong-Chul
authors.initials: BC
authors.lastname: Chu
authors.forename: Russel
authors.initials: R
authors.lastname: Burge
authors.forename: David R
authors.initials: DR
authors.lastname: Diakun
authors.forename: John H
authors.initials: JH
authors.lastname: Krege
mesh_terms: D000368:Aged; D019386:Alendronate / Q000008:administration & dosage*; D015519:Bone Density / Q000187:drug effects; D050071:Bone Density Conservation Agents / Q000008:administration & dosage*; D001943:Breast Neoplasms / Q000453:epidemiology; D015331:Cohort Studies; D015897:Comorbidity; D005260:Female; D006801:Humans; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000188:drug therapy* / Q000453:epidemiology; D058866:Osteoporotic Fractures / Q000453:epidemiology* / Q000517:prevention & control; D020849:Raloxifene Hydrochloride / Q000008:administration & dosage*; D012189:Retrospective Studies; D014481:United States / Q000453:epidemiology; D016387:Women's Health
chemical_list: D050071:Bone Density Conservation Agents; D020849:Raloxifene Hydrochloride; D019386:Alendronate