What Cystic Fibrosis Test is Right for Your Newborn?

IRT/DNA is cheaper and more effective for families than irt/irt

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Recently developed screenings for newborns can help diagnose cystic fibrosis but can be costly. A new study has determined the best cystic fibrosis screening currently available.

Using a simulation of 100,000 newborns, researchers tested two immunoreactive trypsinogen (IRT) screenings and an IRT/DNA analysis to determine the overall costs and benefits to families. While the IRT/IRT test was cheaper for laboratories and insurance companies, the IRT/DNA analysis had lower out-of-pocket cost to families.

"Ask your doctor about available cystic fibrosis tests."

The research was led by Janelle Wells, M.D., M.P.H., from the Departments of Population Health Sciences at the University of Wisconsin. Researchers used computer simulations involving 100,000 newborns which included the cost of using either IRT/IRT or IRT/DNA, cystic fibrosis diagnosis and possible system failures. While IRT/IRT may be cheaper for laboratories or insurance companies, there were more missed cystic fibrosis diagnoses when compared to IRT/DNA. IRT/DNA was also found to have lower out-of-pocket costs for families.

The IRT test requires a blood sample from the newborn. Doctors then examine the blood sample for higher levels of IRT, which is a protein linked to cystic fibrosis. If the results are abnormal, a second IRT test could be performed to help determine if a newborn has cystic fibrosis. An alternative method is to use a DNA test, since cystic fibrosis is genetic, after an initial abnormal IRT test.

While the IRT/IRT was cheaper to perform, it also had higher out-of-pocket costs for families and system malfunctions that delayed diagnosis. Researchers also noted the IRT/IRT test had potentially missed a significant number of cystic fibrosis diagnoses. The IRT/DNA test had fewer systems malfunctions that delayed possible diagnosis.

The computer simulations are effective in determining possible costs as well as possible limitations of both testing methods. Currently, all states perform cystic fibrosis screenings using an IRT test. If the initial IRT test is abnormal, some states perform the second IRT screening while other states perform a DNA screening to diagnosis cystic fibrosis. 

According to the study, the IRT/DNA test provides more accurate results and is the more cost-effective option when compared to IRT/IRT. This study, and future studies, could help create a uniform screening process that can detect cystic fibrosis early which would lead to better treatment.

No funding information was provided. No author conflicts were reported.

This study was published in the January edition of Pediatrics.

Reviewed by: 
Review Date: 
February 8, 2012
Last Updated:
February 10, 2012