#NACFC2021 – Newborn Screening Improves Real-world Outcomes
For children with cystic fibrosis (CF), newborn screening is associated with markedly improved real-world outcomes, including earlier diagnosis, greater weight and height gains, and fewer bacterial infections, new research demonstrates.
In fact, infants are now diagnosed with the genetic disease at a median of 0 months of age — four months sooner than before such screening was available — the research showed.
“We demonstrate that CF NBS [newborn screening] in the United States is associated with improved outcomes through age 9 in a ‘real-world’ setting,” the investigators wrote in the study abstract, noting that their new research design accounted for “improving CF outcomes over time.” changed so substantially since the 1990s
The findings were presented at the 2021 North American Cystic Fibrosis Conference (NACFC), held virtually Nov. 2–5, in a talk titled “The real-world effectiveness of U.S. CF newborn screening.”
Newborn screening, as the name suggests, involves testing babies for CF as soon as they are born. In the U.S., such screenings for CF were implemented in individual states throughout the early 2000s. By 2010, such testing was being done nationwide.
Now, a team of scientists used data from the CF Foundation Patient Registry to identify children with CF born between 2000 and 2009. The goal was to examine the effects of newborn screening programs relative to real-world outcomes.
The researchers compared 4,471 children who were born before newborn screening was implemented in their state, with 5,059 children born after testing had begun where they lived. Among the children, roughly half were female, and more than 90% were white. Blacks comprised about 4% of both the pre- and post-testing groups, while Hispanics accounted for 10.3% of those born before such screening and 11.3% after the implementation of these programs.
“Our objective was to estimate the effect of CF newborn screening programs on longitudinal health outcomes a decade after universal newborn screening was implemented in the United States,” said Margaret Rosenfeld, MD, a professor at the University of Washington, who presented the study at NACFC.
Notably, the analysis did not account for whether or not individual children underwent newborn screening, just whether or not it was available where they lived. The analysis excluded children born the exact year such testing was implemented in their state, as this was assumed to be a transitional time. It also excluded infants born preterm.
The results showed that infants born in the era of newborn screening were diagnosed at a median age of 0 months of age, whereas children born before such screening was offered were diagnosed substantially later, at a median of 4 months of age. Similar differences were seen regardless of the specific type of disease-causing mutations in individual patients.
“In the post-newborn screening era, diagnosis was achieved much earlier compared to pre-newborn screening,” Rosenfeld said.
Using a battery of statistical tests, the team looked for differences between the groups in terms of growth outcomes, lung function, and infections with Pseudomonas aeruginosa, the chief bacteria in CF lung infections. These analyses also accounted for factors like the children’s age and insurance.
Children born in the newborn screening era tended to be in higher percentiles for weight and height. This trend was consistent across all ages studied — 0 to 10 — but tended to be more pronounced in the youngest infants. It did become less substantial with increasing age.
Of note, many people with CF have digestive problems that make it difficult to get enough nutrition, which can limit growth. Thus, these results are indicative of better nutrition in these children.
An initial infection with P. aeruginosa, was significantly less likely — by about 15% — among children born when newborn screening was available. These children also were roughly 31% less likely to have chronic infections with this bacteria. Rosenfeld said the screening had “an apparent protective effect” against such infection.
No significant differences between the groups were found in terms of forced expiratory volume in one second (FEV1), a common measure of lung function, although increasing age was associated with a benefit favoring the post-newborn screening era group. Notably, this analysis only included children ages 6 and older, so it was smaller — and thus less statistically powerful — than analyses for growth or infection.
“We did not see a clear effect on FEV1, though our sample size was smaller,” Rosenfeld said, noting that a longer follow-up time may be needed to detect any association between newborn screening and lifelong lung function.
“Children diagnosed following the introduction of NBS [newborn screening] in their state were more likely to achieve nutritional goals and had lower hazard of initial and chronic P. aeruginosa infection than children born prior to NBS,” the team concluded in their abstract.
Collectively, these data show how newborn screening programs can improve long-term outcomes for children with CF. Rosenfeld noted that, while these programs are effective, they are often making due with less-than-ideal resources.
“I would like to see more resources for departments of health around the country set aside for newborn screening,” she said, noting that even though the number of conditions being tested for by such testing is “exploding,” resources and staff available to these programs — particularly during the COVID-19 pandemic — haven’t increased much.
“Newborn screening programs are just absolutely strapped, and when I talk to them, they’re so cognizant that they’re not able to do as good a job … as they’d like to, because of not having enough personnel,” Rosenfeld said.
Editor’s note: The Cystic Fibrosis News Today team is providing coverage of the virtual 2021 North American Cystic Fibrosis Conference (NACFC) Nov. 2-5. Go here to see the latest stories from the conference.
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