title: Oral bisphosphonates may not decrease hip fracture risk in elderly Spanish women: a nested case-control study.
abstract: OBJECTIVE
  To evaluate the association between the long-term use of bisphosphonates and the risk of hip fracture compared to never use among women aged 65 years or older.
  
  
  METHODS
  Case-control study nested in a cohort.
  
  
  METHODS
  General practice research database operated by the Spanish Medicines Agency.
  
  
  METHODS
  Cases of hip fracture were defined as women aged 65 years or older with a validated first diagnosis of hip fracture between 2005 and 2008. Five controls free of hip fracture were matched on age and calendar-year with each case.
  
  
  METHODS
  Information on bisphosphonate use, hip fractures, comedication and comorbidities was collected.
  
  
  METHODS
  Hip fracture risk comparing bisphosphonate users versus never users.
  
  
  RESULTS
  Hip fracture risk comparing bisphosphonate users versus never users by individual drugs.
  
  
  RESULTS
  The study included 2009 incident hip fractures and 10 045 matched controls. Hip-fracture risk did not differ between bisphosphonate users and never users, adjusted OR=1.09 (95% CI 0.94 to 1.27). No association was observed between hip fracture risk and cumulative duration of bisphosphonate treatment. However, when treatment duration is analysed as time since first prescription, hip fracture risks of the different subgroups compared to never users obtained were as follows: <1 year, OR 0.85 (95% CI 0.60 to 1.21); 1 to <3 years, OR 1.02 (95% CI 0.82 to 1.26); ≥3 years, OR 1.32 (95% CI 1.05 to 1.65) (p for trend=0.03).
  
  
  CONCLUSIONS
  Ever use of oral bisphosphonates was not associated with a decreased risk of hip fracture in women aged 65 or older as compared to never use. No association was observed between hip fracture risk and cumulative duration of bisphosphonate treatment. However, when treatment duration is analysed as time since first prescription, a statistically significant increased risk for hip fracture was observed in patients exposed to bisphosphonates over 3 years.
  
  
  BACKGROUND
  Spanish Ministry of Health. TRA-071.
authors: Drug Prescribing Service,  Navarre Regional Health Service, Pamplona, Navarre,  Spain.
authors: Juan
authors: J
authors: Erviti
authors: Alvaro
authors: A
authors: Alonso
authors: Javier
authors: J
authors: Gorricho
authors: Antonio
authors: A
authors: López