Older women who use bisphosphonate for longer than 5 years may have increased odds of a subtrochanteric or femoral shaft fracture, but absolute risk is low
- Department of Medicine, Gentofte Hospital, Copenhagen, Denmark
- Correspondence to Bo Abrahamsen
Department of Medicine, Gentofte Hospital, Niels Andersensvej 65 Hellerup DK-2900, Denmark;
It is now recognised that fractures of the subtrochanteric femur or femoral shaft (ST/FS fractures) can be divided radiologically into (1) typical fractures and (2) atypical fractures. The latter appear to be rare in patients untreated by bisphosphonates. In this new study, Park-Wyllie et al used Ontario claims data to investigate the association between the amount of bisphosphonates taken and the risk of ST/FS fractures.
The study was a nested 5:1 case-control study, linking prescriptions with hospitalisations, physician service claims and death certificates. Women aged 68 years or older who filled prescriptions for bisphosphonates at least once over a 6-year period were included. Those with malignant disease in the past 10 years, specific bone diseases or secondary causes of osteoporosis (past 5 years) and osteoporosis treatment in the past year were excluded, providing 205 466 women for study.
Cases were defined as first ST/FS fracture, excluding fractures treated …