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It's high time the United States established a broad, uniform panel of newborn screening tests, say pediatric experts, and the results of a study released in May by the Indiana University School of Medicine suggest such a program would save healthcare dollars as well as lives.

"It was surprising, certainly to me, anyway," says Dr. Stephen M. Downs, who conducted the research along with colleague Dr. Aaron E. Carroll. "Because some of these conditions are so rare, it seemed to me that it was going to be difficult to offset the cost of testing every single newborn for all of these disorders. But what we found, in fact, is that the cost of not finding these conditions, even in only a few children, would more than offset the cost of testing to find them early." Drs. Downs and Carroll weighed the cost of testing, the cost of treating the disorders and the cost to society if the conditions were not treated early. They also factored in false positives and the prevalence of the disorders.

"The kind of analysis we did is fairly complex, and we only looked at about eight conditions," Downs explains. "But the trend that we found is that as we began looking for more conditions given the same testing technology, it really just made the picture look better. The bottom line is that testing for conditions about which we can do something is going to have a payoff in the long run."

According to the federal Centers for Disease Control and Prevention, more than 98 percent of all children born in the United States are tested for treatable diseases such as phenylketonuria, sickle cell disease, congenital hypothyroidism and galactosemia. Each year, at least 4 million babies are tested within 48 hours of their birth, using a blood sample obtained from a heel stick. Severe disorders are detected in about 3,000 newborns annually.

Thanks to tandem mass spectrometry, more than 50 conditions now can be screened for at once using a process called multiplexing. That's why the United States Department of Health and Human Services funded a grant for the Indiana University research, to find out how many conditions could be screened for before the costs outweighed the health benefits. The answer? As many as you want.

Last year, the American College of Medical Genetics, after three years of study, recommended nationwide screening for 29 disorders. Currently, the number of disorders screened for is determined on a state-by-state basis — fewer than 10 in Texas and 53 in the District of Columbia. Tests using multiplex technology cost between $1.90 and $25.

Downs cautions that a newborn screening program "is more than just the test. It's the test and then having the medical community prepared to respond to the test. The primary care physician for these children has to be prepared to respond to these newborn screening tests when they come back positive and to help parents understand that this is a preliminary test."

One pervasive issue with newborn screening is the number of false positives, which takes a toll on parents and providers. Studies suggest that for every one positive identification, there are probably 12 false positives. Of course, as the number of disorders screened for increases, the number of false positives will go up as well. "False positives have certainly been an issue that's been raised and, in fact, I've been one of the people who raised this issue in the past," Downs says.

Just what is a false positive? Susan Waisbren, PhD, a psychologist with Children's Hospital Boston, says a false positive "is not really a mistake. It's an initial, out-of-range screening result. … These are usually transient findings. The cutoff is purposely set to be very sensitive so children who really do have the disease aren't missed. They err on the side of the false positive, because missing any children could have dire consequences."

Waisbren and colleague Elizabeth Gurian have studied the effects of false positives on parents and families. They reported in the June issue of Pediatrics, the journal of the American Academy of Pediatrics, that a false positive results in lingering anxiety, even after a secondary test rules out any problems.

"The research was part of a broader study on parental response to expanded newborn screening. We recognized that, with expansion of screening, there were going to be more parents whose children had a false-positive identification just because there were more diseases being screened for," Waisbren explains. Her study involved interviews with 173 families who had received false-positive screening results and a comparison group of 67 families with normal newborn screening results. Although mothers in the false-positive group were interviewed at least six months after their child's diagnosis had been ruled out, they reported more worry about their child's future and rated themselves less healthy than mothers in the comparison group. Their expectations of future illness were higher than the control group, as well, and they took their children to healthcare providers more often. False positives also affect parent-child relationships, the study showed, with parents expressing a desire for a closer, warmer bond and believing their false-positive child makes more demands on them.

Waisbren says follow-up research with physicians found that 54 percent were "less than comfortable" talking about screening results with families and 75 percent wanted more information to give to families.

"What we've found — and I think this is the take-home message — is that improved parental education would reduce the stress that parents feel at a false positive. Secondly, the timing of this information is important," she says. Parents should first hear about newborn screening well before the baby arrives and again before they receive results of the test. Finally, doctors and parents "should sit down and review the results, whether good or bad. If all that happened, I think parents would not be so anxious. Our data indicated that families who had better knowledge were less stressed."

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