The New York Times had an excellent article on newborn screening tests.
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Panel to Advise Testing Babies for 29 Diseases. Kolata G. The New York Times,
February 21, 2005.
Unfortunately, this article is no longer available online. But it discusses a recent push
to standardize and expand the screening tests for newborns to include 29 different diseases.
It seems like such an obvious thing to do: let's screen for these conditions, because the
more we know, the better we are able to care for these children.
Proponents say that the diseases are terrible and that an early diagnosis can be
lifesaving. When testing is not done, parents often end up in a medical odyssey to find
out what is wrong with their child. By the time the answer is in, it may be too late for
treatment to do much good.
Opponents, however, point out that false positive results may present more problems.
But opponents say that for all but about five or six of the conditions, it is not
known whether the treatments help or how often a baby will test positive but never show
signs of serious disease. There is a danger, they say, of children with mild versions of
illnesses being treated needlessly and aggressively for more serious forms and suffering
dire health consequences.
The article also offers a historical perspective.
The history of newborn screening, they say, is filled with cautionary tales.
%22The majority of newborn screening tests have failed,%22 said Dr. Norman Fost, a
professor of pediatrics and director of the program in medical ethics at the University
of Wisconsin. Over the years, Dr. Fost said, %22thousands of normal kids have been
killed or gotten brain damage by screening tests and treatments that turned out to be
ineffective and very dangerous.%22
and cites phenylketonuria (PKU) testing as an example.An infant with PKU cannot metabolize
phenylalanine, and the build up of this amino acid can lead to serious neurological damage.
The treatment, a diet low in phenyalanine, is very effective, but only if the condition is
diagnosed early. The PKU testing done today is very good, but tests performed 45 years ago
had problems.
Back then, any infant who tested positive would be put on this special diet. When
phenylalanine is withdrawn from the diet of a healthy infant, that infant suffers from even
more serious neurological problems and can even die. Many infants who falsely tested positive
were put on this diet and their harms outweighed the benefits of PKU screening. As
researchers learned more, they were able to refine the test to prevent most false positives,
but the damage had already been done.
An additional article about Universal Newborn Hearing Screening (UNHS),
This article ultimately concludes that with a reduction in the false positive rate, that
the benefits of UNHS outweigh the costs.
I'm trying to develop a good set of web pages on diagnostic
testing, but there is a lot of work that I need to do. I also offer a couple of training
classes that discuss diagnostic tests:
07/08/2008.
