The US FRAX® filter: avoiding confusion or hindering progress?
J. Compston Cambridge University Hospitals NHS Foundation Trust
, Cambridge CB2 0QQ,
Donald Rumsfeld US Department of Defence News Briefing
, July 2003
) Academic Unit of Bone Metabolism, University of Sheffield
, Sheffield S5 7AU,
C. Cooper MRC Epidemiology Resource Centre, University of Southampton
The leadership of NOF and ISCD has decided after long and
careful consideration that a FRAX filter should be available,
and this will happen in the USA. So speak the proponents of
the US FRAX filter. Unfortunately, the careful consideration
appears to have been driven more by threat than opportunity.
In the absence of publication of the in-depth reasons, the only
argument, regrettably, appears to be that of maintaining the
status quo, justified under the flag of minimising confusion.
The question remains as to who is confused? The concept of
combining risk factors to provide an estimate of risk that can
then drive intervention is well established in many disease
areas, particularly in cardiovascular disease. Most clinicians,
even non-expert ones, understand this and it has made a
dramatic impact on health outcomes.
The failure to perceive FRAX not only as a risk
calculator but also an educational tool that opens access to
better management implies that the NOF and ISCD regard
clinicians in the US as less capable than elsewhere. If their
purpose is to eliminate uncertainty, then it follows that
information on BMD at sites other than the femoral neck or
lumbar spine should be filtered in all bar exceptional
circumstances. It also follows that BMD should not be
reported in patients on treatment, nor T-scores in
premenopausal women. The list is endless. An alternative
interpretation is that they espouse protectionism over a
disease that should lie within the remit of every capable
clinician to manage appropriately, referring to expert
centres when necessary.
The objective of FRAX, conceived and developed in
close collaboration with the NOF and ISCD, is to provide
clinicians and patients with information on fracture risk that
adds to that derived from BMD alone. For the NOF to
retreat from this by only partially implementing FRAX
seems both short sighted and misguided. There is no gold
standard and to regard BMD thresholds as such does the
whole field a disservice. Of course, it is true that situations
will arise where the calculated fracture probability might
suggest that guidance based on BMD alone is misleading.
This scenario is equally likely, if not more so, to represent
the shortcomings of the use of BMD alone rather than the
use of fracture probabilities. Drs Cummings and Bauer
eloquently illustrate such a clinical scenario in their
arguments against applying the filter . Indeed, it is the
discrepancies that highlight the purpose of FRAX,
educate the physician and the patient and, it is hoped,
better inform and direct management decisions. The
quagmire only arises if we lose sight of these goals.