Late diagnosis of cystic fibrosis leads to poorer long-term health outcomes, study finds

Reviewed by Danielle Ellis, B.Sc.Jul 31 2023

The Journal of Pediatrics has published a manuscript by Stacey Martiniano, MD, pulmonary specialist at Children's Hospital Colorado and associate professor of pediatrics at the University of Colorado. Dr. Martiniano was primary author on the study titled, Late Diagnosis in the Era of Universal Newborn Screening Negatively Effects Short- and Long-Term Growth and Health Outcomes in Infants with Cystic Fibrosis. The manuscript's senior author was Susanna McColley, MD, pulmonologist at Ann & Robert H. Lurie Children's Hospital of Chicago and professor of pediatrics in pulmonary and sleep medicine at Northwestern University Feinberg School of Medicine. The research was funded by the Cystic Fibrosis Foundation.

Newborn screening for cystic fibrosis (CF) was fully implemented in all 50 states in the U.S. by 2010, but delays in timeliness of evaluation for infants with positive newborn screen tests persist. Through evaluation of national patient registry data, Dr. Martiniano and her team determined that later initiation of CF care is associated with poorer long-term nutritional outcomes. Specifically, a delay in initial care at a CF center from just 10 days of life to 47 days of life was associated with reduced weight-for-age through 1 year of age and reduced height-for-age through 5 years of age. These are clinically important findings because early life weight-for-age and height-for-age are associated with later pulmonary function and survival.

It is imperative that not only do we not miss diagnosing babies with CF, but that we also emphasize urgent referral for newborn screen follow-up for babies with an out-of-range screen, including sweat testing and referral for care at an accredited CF care center."

Dr. Stacey Martiniano, MD, pulmonary specialist at Children's Hospital Colorado and associate professor of pediatrics at the University of Colorado

Infants in the later cohort most commonly had a sweat test as their first CF evaluation and were more likely to have only one CF gene variant detected on commercially available panels used by most newborn screening programs. This may have caused a diminished sense of urgency to get the infants evaluated possible leading to delays in treatment based on a false assumption that two variants would be detected if the infant had CF.

"This will allow all babies with CF to be equitably started on treatments, with a goal before 1 month of age, to have improved long-term health outcomes," Dr. Martiniano said. This is especially important today due to emergence of ground-breaking, disease-modifying treatment available for infants and young children with CF."

CF is an inherited disorder that affects the lungs, digestive system and other organs in the body. The disorder disrupts the normal function of epithelial cells, which line passageways in the respiratory tract, digestive system, sweat glands and reproductive system. Because cystic fibrosis impacts so many organs, it can disrupt many of the body's essential functions.

"Our previous work has demonstrated that, since CF newborn screening was implemented throughout the US, about one of every three babies with CF has their initial visit to a CF Center after one month of age. These findings give further evidence that adherence to published guidelines, which call for diagnosis and treatment by 28 days of age, is important to give each baby with CF the chance of the healthiest possible start," said Dr. McColley. "Notably, the later diagnosed infants had a median age of 47 days-;just under 7 weeks---and still had significantly worse early life health outcomes. Public health, primary care and cystic fibrosis center professionals must come together to improve timeliness and efficiency so that all babies with a positive newborns screening tests are seen promptly."