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Value of routine monitoring of bone mineral density after starting bisphosphonate treatment: secondary analysis of trial data

BMJ 2009; 338 doi: (Published 24 June 2009) Cite this as: BMJ 2009;338:b2266
  1. Katy J L Bell, research fellow1,
  2. Andrew Hayen, senior lecturer in biostatistics1,
  3. Petra Macaskill, associate professor of biostatistics1,
  4. Les Irwig, professor of epidemiology1,
  5. Jonathan C Craig, professor of clinical epidemiology1,
  6. Kristine Ensrud, professor of medicine2,
  7. Douglas C Bauer, professor of medicine and epidemiology and biostatistics3
  1. 1Screening and Test Evaluation Program, School of Public Health, Edward Ford Building (A27), University of Sydney, NSW 2006, Australia
  2. 2University of Minnesota Medical School, Veterans Affairs Medical Center, One Veterans Drive (111-0), Minneapolis, MN 55417, USA
  3. 3Box 0560, 185 Berry Street 5700, University of California, San Francisco, CA 94143–0560, USA
  1. Correspondence to: K J L Bell katyb{at}
  • Accepted 5 February 2009


Objective: To assess the value of monitoring response to bisphosphonate treatment by means of measuring bone mineral density.

Design Secondary analysis of trial data using mixed models.

Data source The Fracture Intervention Trial, a randomised controlled trial that compared the effects of alendronate and placebo in 6459 postmenopausal women with low bone mineral density recruited between May 1992 and May 1993. Bone density measurements of hip and spine were obtained at baseline and at one, two, and three years after randomisation.

Main outcome measures Between-person (treatment related) variation and within-person (measurement related) variation in hip and spine bone mineral density.

Results The mean effect of three years’ treatment with alendronate was to increase hip bone mineral density by 0.030 g/cm2. There was some between-person variation in the effects of alendronate, but this was small in size compared with within-person variation. Alendronate treatment is estimated to result in increases in hip bone density ≥0.019 g/cm2 in 97.5% of patients.

Conclusions: Monitoring bone mineral density in postmenopausal women in the first three years after starting treatment with a potent bisphosphonate is unnecessary and may be misleading. Routine monitoring should be avoided in this early period after bisphosphonate treatment is commenced.


  • Contributors: KJLB conceived the study, did the analysis and wrote the paper. AH helped with the analysis and helped write the paper. JCC and KE helped write the paper. PM and LI helped supervise the analysis and write the paper. DCB provided the raw data and assisted with manuscript revisions. KJLB is guarantor for the study.

  • Funding: This study was funded by the Australian National Health and Medical Research Council (Public Health Postgraduate Research Scholarship No 457212 and Program Grant No 402764 ). The Fracture Intervention Trial was sponsored by Merck Research Laboratories.

  • The sponsors did not influence the design and conduct of the study; collection, management, analysis, and interpretation of data; preparation and approval of the manuscript; or decision to submit the article for publication. All of the researchers involved in this project are independent of the funding bodies.

  • Competing interests: DCB has received honorariums from Merck, Procter & Gamble, Amgen, Roche Diagnostics, and Novartis; and research support from Procter & Gamble, Novartis, and Amgen.

  • Ethical approval: Ethical approval was not required for this study.

This is an open-access article distributed under the terms of the Creative Commons Attribution Non-commercial License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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