Stephen J.LurieMD, PhD, Senior EditorIndividualAuthor
In Reply: It is encouraging that Dr Liou and
colleagues carefully considered the potential impact of the rate of fall of
FEV1% in developing their model for predicting survival in patients
with cystic fibrosis. They state that despite a variety of iterations of the
model they were unable to find an impact on the survival predictions, and
they conclude unequivocally that "the rate of decline in FEV1%
is not helpful in the selection of candidates with CF for lung transplantation."
However, they also note that this clinical parameter has been identified as
a negative predictor by several other authors.1- 3
It is important to remember that the model has not yet been validated prospectively
in patients with CF who are within their last years of life. The disparity
between the model of Liou et al and other published data in predicting 5-year
survival likely reflects the different populations studied. Authors who have
identified the rate of decrease in FEV1% as an important predictor
have generally not looked at the whole population of patients who might be
included in a 5-year survival prediction model, but rather at a smaller subset
of patients, a "self-selected" group, who are rapidly deteriorating clinically.
In this population, the rate of decline of FEV1 might indeed be
helpful to caregivers and transplant centers in determining appropriate times
to wait-list patients. Whether the addition of this type of parameter to the
predictions of the model of Liou et al adds useful information for clinicians
will become clear as it is evaluated prospectively.
Maurer JR. Priorities for Lung Transplantation Among Patients With Cystic Fibrosis—Reply. JAMA. 2002;287(12):1523-1525. doi:10.1001/jama.287.12.1523