A Johns Hopkins transplant surgeon has found strong
evidence that women over 45 are
significantly less likely to be placed on a kidney
transplant list than their male counterparts, even
though women who receive a transplant stand an equal chance
of survival.
"As women age, that discrepancy widens to the point
where women over 75 are less than half as
likely as men to be placed on a kidney transplant list,"
said lead researcher Dorry Segev, a
transplant surgeon at Johns Hopkins. "If the women have
multiple illnesses, the discrepancy is even worse."
In a new study, appearing online Jan. 7 in the
Journal of the American Society of Nephrology,
Segev and his team looked at data from the United States
Renal Data System kidney transplant list of
563,197 patients who developed first-onset end-stage renal
disease between 2000 and 2005. USRDS
tracks all patients who start dialysis, get placed on the
transplant waiting list or receive a
transplanted organ. The likelihood of getting on a
transplant list was calculated after adjusting for
factors that determine the patient's relative rate of
survival after transplantation compared to
dialysis.
When the results were stratified for age, the
likelihood that women ages 18 to 45 made it onto
the transplant list was equivalent to that of men. However,
as women's age increased, their likelihood
of being placed on the transplant list fell incrementally.
Women ages 46 to 55 were 3 percent less
likely to be put on the list, women 56 to 65 were 15
percent less likely, women 66 to 75 were 29
percent less likely, and women 75 or older were 59 percent
less likely. These disparities existed
whether the recipient was seeking a deceased- or live-donor
kidney. The chance of a woman getting
listed was worse if she had additional diseases such as
diabetes or heart disease.
Segev said he believes the gap is the result of what
he calls an unsubstantiated "perceived
frailty" of women that factors subconsciously into the
listing process. Two main steps determine who
is placed on the United Network for Organ Sharing kidney
transplant list: referral by a nephrologist
and the patient's acting on that referral.
"It appears as though either the nephrologist believes
women have a worse chance of survival or
some women don't think they will have a good outcome,"
Segev said. "Once they are listed, however,
women and men have an equal chance of getting a kidney,
regardless of age."
Segev said that this "perceived frailty" has no basis
in fact. For every age group analyzed in
this study, women had similar or slightly higher survival
rates after transplantation than men.
"This is different from most factors that create
access to transplant disparities, such as
obesity and race," Segev said. "Those disparities continue
even once you've been listed — for example,
blacks are less likely to get listed and, once they're
listed, are also less likely to receive a transplant."
Other researchers from the Johns Hopkins University
School of Medicine who contributed to
this study are Robert Montgomery and Lauren M. Kucirka,
both of the Department of Surgery; and
Pooja C. Oberai, Rulan S. Parekh, L. Ebony Boulware and
Neil R. Powe, all of the Department of
Medicine.