Details strengths and limitations of the tool, provides recommendations for using surrogate country models
FRAX® is a computer-based algorithm developed by the World Health
Organization Collaborating Centre for Metabolic Bone Diseases to help predict
the 10-year risk of fragility fracture. Now with 34 specific country models,
FRAX is being used increasingly by physicians around the world to help assess
their patients’ fracture risk in the course of a clinical assessment.
In
a newly published review paper, the International Osteoporosis Foundation (IOF)
and the International Society for Clinical Densitometry (ISCD) detail the
findings of a joint Task Force that met in November 2011 for the ‘ISCD IOF FRAX
Initiative’ meeting. The objective was to make recommendations on how to improve
FRAX and better inform clinicians using the tool.
“FRAX is a widely
accepted reference platform that allows physicians to make more informed
clinical assessments of their patients. Nevertheless, they should be aware of
the tool’s limitations and take these into consideration when assessing patients
for further testing or pharmacological treatment,” said Dr. Didier Hans,
co-chair of the FRAX Initiative and immediate past president of the ISCD.
“Indeed, although FRAX scores provide empirical evidence to better guide
intervention, clinical judgment is paramount.”
The review clarifies a
number of important questions pertaining to the interpretation and use of FRAX
in clinical practice and highlights both perceived strengths and limitations. It
provides details on the clinical risk factors currently used and explains the
reasons for the exclusion of other risk factors. Several of the key issues
discussed include:
Strengths:
- FRAX has been validated in 11 independent cohorts covering in excess of 1 million patient years. The model determines the predictive importance of each clinical risk factor, as well as interactions between them, to optimize the accuracy of fracture probability.
- FRAX models are based on country-specific data. Unlike more simple risk models, the tool integrates mortality as well as age-specific fracture rate statistics.
- FRAX is appreciated for its simplicity for use in primary care. It is primarily used as a clinical tool to help physicians assess fracture probability as an aid in identifying which individuals may be candidates for reassurance, bone density evaluation or pharmacological treatment. FRAX is also used for guideline development, drug registration and health economic applications.
- The tool is freely accessible online. As well, it is available via iPhone,
as a hand held calculator, and is integrated in densitometry technology. It is
available in 16 languages and a growing number of country models (currently 40
models for 34 countries).
Limitations: - FRAX does not take into account all risk variables of which the physician should be aware. These include, for example, the risks associated with falls, markers of bone turnover levels, other bone density assessments, as well as certain secondary causes of osteoporosis.
- For most clinical risk factors, FRAX uses yes/no answers and the average risk is computed. It therefore does not take into account the variation of risks associated with high or low doses of glucocorticoids, the number and type of prior fractures, or the quantity of alcohol or tobacco consumption.
- Other limitations of FRAX are dictated by the current scientific evidence available. FRAX does not take into consideration patients on treatment, younger men and women, variations of fracture rates within countries and changes of country-specific fracture rates over time.
In countries not yet included in FRAX, physicians may use surrogate country
models, preferably choosing a surrogate model country which best approximates
the fracture risk and death hazard of the index country.
Professor Cyrus
Cooper, chair of the IOF Committee of Scientific Advisors and co-chair of the
ISCD IOF FRAX Initiative, commented, “FRAX represents a significant advance
which has facilitated the assessment of osteoporosis-related fracture risk to
aid clinicians in identifying high risk subjects. Given the widespread use and
interest in FRAX and its adoption in an increasing number of management
guidelines around the world, we must ensure that clinicians worldwide are well
informed and aware of best practice in the use of this important new tool.”
Interpretation and use of FRAX in clinical practice. Osteoporos Int.
2011.
DOI: 10.1007/s00198-011-1713-z. Available at http://www.springerlink.com/content/k4181054x0t88346/
ENDS
About IOF
The International
Osteoporosis Foundation (IOF) is a non-profit, nongovernmental umbrella
organization dedicated to the worldwide fight against osteoporosis, the disease
known as “the silent epidemic”. IOF’s members – committees of scientific
researchers, patient, medical and research societies and industry
representatives from around the world – share a common vision of a world without
osteoporotic fractures. IOF now represents 199 societies in 93 locations. http://www.iofbonehealth.org
About
ISCD
The International Society for Clinical Densitometry (ISCD) is
an international non-profit professional society linking multiple disciplines
with an interest in bone mass measurement and assessment of skeletal integrity.
ISCD's mission is to Advance Excellence in Skeletal Health Assessment by:
Promoting education and a broader understanding of the clinical applications of
bone mass measurement and other skeletal health assessment technologies;
Assuring proficiency and quality in the assessment of skeletal health through
certification and accreditation; Supporting clinical and scientific advances in
the diagnosis and treatment of osteoporosis; and, Promoting appropriate patient
access to bone mass measurement and other skeletal health assessment
technologies. http://www.iscd.org/
