Oral bisphosphonates are associated with increased risk of atypical femoral fractures in elderly women

Objectives: To evaluate the association between bisphosphonate use and the risk of atypical femoral fractures among women aged 65 or older. Design: Nested case–control study. Setting: General practice research database in Spain. Exposures Use of oral bisphosphonates before the occurrence of atypical fractures among cases or the corresponding index date among controls. Bisphosphonate use was categorised as ever versus never users. Ever users were divided according to the total time since first prescription. Main outcome measures: Cases were defined as women aged 65 years or older with a first diagnosis of subtrochanteric or diaphyseal fracture, recorded in the BIFAP database between 1 January 2005 and 31 December 2008, and with at least 1 year of follow-up before the index date. For each case, five age-matched and calendar-year-matched controls without a history of hip or atypical fracture were randomly selected from the database. Statistical analysis: OR of atypical femoral fracture by ...