Long-term bisphosphonate use and risk of atypical femur (thigh) fractures

Pooling International Cohort Studies of Long-Term Bisphosphonate Use and Atypical Femur Fractures

NIH-funded research University of California, San Francisco · NIH-11383104

This project combines data from several large groups to understand how long-term use of bisphosphonate bone medicines affects the chance of rare atypical thigh fractures in people taking them.

Quick facts

Grant typeR01 grant
Study typeNIH-funded research
Funding institutionUniversity of California, San Francisco NIH-funded
Lab location1 site (San Francisco, United States)
Project IDNIH-11383104 on NIH RePORTER

What this research studies

Researchers are pooling individual-level data from multiple large, population-based cohorts that have X-ray-confirmed atypical femur fractures and detailed long-term medication records. They will harmonize definitions and run centralized statistical analyses to compare fracture risk by duration of bisphosphonate use and by periods off the drug (drug holidays). The team will look for subgroups, especially among women, who have higher or lower risk to help guide choices about starting, continuing, or pausing treatment. By combining datasets, they aim to get more precise risk estimates for these rare events than any single study can provide.

Who could benefit from this research

Good fit: People taking or considering long-term bisphosphonate treatment for osteoporosis—particularly postmenopausal women—are the group most relevant to these findings.

Not a fit: People who do not have osteoporosis or are not using bisphosphonates, and populations not well represented in the pooled cohorts, may not directly benefit from the results.

Why it matters

Potential benefit: If successful, this work could help patients and doctors weigh the benefits of fracture prevention against the small risk of atypical femur fractures and personalize how long bisphosphonates are used.

How similar studies have performed: Previous studies have linked long-term bisphosphonate use to atypical femur fractures but these events are rare, so pooling multiple cohorts to get clearer risk estimates is a promising and relatively novel approach.

Where this research is happening

San Francisco, United States

Researchers

About this research

  1. This is an active NIH-funded research project — typically early-stage science, not a clinical trial accepting patient enrollment.
  2. Some NIH-funded labs run parallel clinical studies or seek volunteers for related work. To check, contact the principal investigator or institution listed above.
  3. For full project details, budget, and progress reports, visit the official NIH RePORTER page below.
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.