Osteoporosis International

, Volume 18, Issue 12, pp 1595–1600

Hip fractures in users of first- vs. second-generation bisphosphonates

Original Article

DOI: 10.1007/s00198-007-0446-5

Cite this article as:
Mamdani, M., Kopp, A. & Hawker, G. Osteoporos Int (2007) 18: 1595. doi:10.1007/s00198-007-0446-5

Abstract

Summary

This study compared population hip fracture rates for women with a prior fragility fracture who were treated with first-generation versus second-generation bisphosphonate therapies. The observational study found that, relative to women treated with etidronate, a first-generation bisphosphonate, women treated with the second-generation therapies ‘alendronate’ or ‘risedronate’ were equally likely to be admitted to hospital for hip fracture. Our findings must be confirmed in large randomized head-to-head controlled trials.

Introduction

Few studies have examined hip fracture outcomes among users of first- versus second-generation bisphosphonates. We compared hip fracture rates among elderly women with a history of fracture dispensed first- and second-generation bisphosphonates, hypothesizing that hip fracture rates would be higher among users of first- versus second-generation bisphosphonates after adjusting for confounders.

Methods

Administrative data from Ontario, Canada from 01 April 1998 to 31 March 2002 was used to identify population-based bisphosphonate-naïve cohorts of subjects age 66 years and older initiated on first- (etidronate plus calcium; n = 19,127) or second-generation (alendronate or risedronate; n = 1,460) bisphosphonates. Multivariate Cox proportional hazard models were used for analysis.

Results

During over 23,000 person-years of follow-up, we observed 293 hospital admissions for first hip fracture. The unadjusted event rates yielded approximately 12.5 hospital admissions for hip fracture per 1,000 person-years of follow-up in each study group. Relative to the etidronate plus calcium group, females in the alendronate or risedronate group were equally likely to be admitted for hip fracture (adjusted rate ratio [aRR] = 1.0; 95% CI 0.6–1.6).

Conclusions

The findings of this study suggest similar rates of hip fracture between the first- and second-generation bisphosphonates when used continuously among elderly females with a prior history of fracture.

Keywords

BisphosphonatesHip fracturesObservational cohort studyPostmenopausal osteoporosis

Copyright information

© International Osteoporosis Foundation and National Osteoporosis Foundation 2007

Authors and Affiliations

  1. 1.Keenan Research CentreLi Ka Shing Knowledge Institute of St. Michael’s HospitalTorontoCanada
  2. 2.Institute for Clinical Evaluative SciencesTorontoCanada
  3. 3.University of Toronto Faculty of PharmacyTorontoCanada
  4. 4.University of Toronto Faculty of MedicineTorontoCanada
  5. 5.Women’s College HospitalTorontoCanada
  6. 6.Department of Health Policy, Management and EvaluationUniversity of TorontoTorontoCanada