title: Warfarin therapy and risk of hip fracture among elderly patients.
abstract: OBJECTIVE
  To ascertain the relationship between warfarin therapy and subsequent hip fracture in a large elderly population.
  
  
  METHODS
  Retrospective, population-based cohort study.
  
  
  METHODS
  Population-based health care administrative databases for Ontario, Canada.
  
  
  METHODS
  Elderly patients receiving warfarin (52,701 patients), thyroid replacement therapy (40,555), an oral corticosteroid (43,915), or a proton pump inhibitor (60,383). The proton pump inhibitor group served as controls.
  
  
  RESULTS
  The association between warfarin therapy and subsequent hospitalization for hip fracture in elderly patients was examined by researching administrative data from January 1, 1994-March 31, 1999, for the elderly population of Ontario. Relative to patients receiving proton pump inhibitors, patients receiving warfarin (adjusted risk ratio [aRR] 0.94, 95% confidence interval [CI] 0.81-1.09) or thyroid replacement therapy (aRR 1.02, 95% Cl 0.89-1.18) incurred similar risks of hip fracture. As expected, patients receiving oral corticosteroids incurred an increased risk (aRR 1.44, 95% CI 1.21-1.70) relative to patients receiving proton pump inhibitors.
  
  
  CONCLUSIONS
  Warfarin was not associated with increased risk of hip fracture.
authors.affiliation: Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada. muhammad.mamdani@ices.on.ca
authors.forename: Muhammad
authors.initials: M
authors.lastname: Mamdani
authors.forename: Ross E G
authors.initials: RE
authors.lastname: Upshur
authors.forename: Geoff
authors.initials: G
authors.lastname: Anderson
authors.forename: Bill R
authors.initials: BR
authors.lastname: Bartle
authors.forename: Andreas
authors.initials: A
authors.lastname: Laupacis
mesh_terms: D000305:Adrenal Cortex Hormones / Q000008:administration & dosage / Q000009:adverse effects; D000368:Aged; D000897:Anti-Ulcer Agents / Q000008:administration & dosage / Q000009:adverse effects; D015331:Cohort Studies; D005260:Female; D006620:Hip Fractures / Q000139:chemically induced* / Q000453:epidemiology; D006801:Humans; D008297:Male; D009864:Ontario / Q000453:epidemiology; D054328:Proton Pump Inhibitors; D012189:Retrospective Studies; D012306:Risk; D013963:Thyroid Hormones / Q000008:administration & dosage / Q000009:adverse effects; D014859:Warfarin / Q000008:administration & dosage / Q000009:adverse effects*
chemical_list: D000305:Adrenal Cortex Hormones; D000897:Anti-Ulcer Agents; D054328:Proton Pump Inhibitors; D013963:Thyroid Hormones; D014859:Warfarin