Newborn Screening for Cystic Fibrosis: Infant and Laboratory Factors Affecting Successful Sweat Test Completion

Ambika Shenoy,Aaron Chidekel,Kathleen Peeke,Dawn Smith,Dina Spyropoulos,Michael Cellucci

doi:10.3390/ijns7010001

Abstract

Newborn screening (NBS) for Cystic Fibrosis (CF) has revolutionized the diagnosis of this inherited disease. CF NBS goals are to identify, diagnose, and initiate early CF treatment to attain better health outcomes. Abnormal CF NBS infants require diagnostic analysis via sweat chloride testing (ST). During ST, insufficient sweat volume collection causes a “quantity not sufficient” (QNS) test result and may delay CF diagnosis. The CF Foundation recommends QNS rates <10% for infants <3 months, but many CF Centers experience difficulties meeting this standard. Our quality improvement (QI) study assessed infant and laboratory factors contributing to ST success and QNS rates from 2017–2019. Infants’ day of life (DOL) at successful ST completion was analyzed according to infant factors (birth weight (BW), gestational age, ethnicity, and sex). Laboratory factors and procedures affecting ST outcomes were also reviewed. At our institution, BW and gestational age were the infant factors found to significantly affect DOL at ST completion. ST education, reduced number of laboratory technicians, and direct observation during ST completion also improved ST success rates. This study supports QI measures and partnerships between CF centers and laboratory staff to identify and improve ST QNS rates while sustaining practices to ensure timely CF diagnostic testing.

Highlights

Cystic fibrosis (CF) is a life-threatening, genetic condition affecting approximately1/3500 births annually in the United States [1]
The European Cystic Fibrosis Society Patient Registry Report in 2018 stated that 74% of CF patients aged 5 years had undergone CF Newborn screening (NBS) at birth. These data support additional quality improvement (QI) in CF NBS to better understand the current screening practices in place, identify factors contributing to delays in diagnostic testing and identify barriers to receiving specialized CF multidisciplinary, clinical, and psychosocial care
160 infants with abnormal CF NBS were referred between January 2017 through December 2019 for additional diagnostic testing

Summary

Introduction

Cystic fibrosis (CF) is a life-threatening, genetic condition affecting approximately1/3500 births annually in the United States [1]. The goal of CF NBS is to achieve early CF diagnosis so that comprehensive medical and psychosocial therapies can be implemented in infants prior to the onset of clinical symptoms to ensure better disease outcomes [3,4,5,6,7,8]. The European Cystic Fibrosis Society Patient Registry Report in 2018 stated that 74% of CF patients aged 5 years had undergone CF NBS at birth (https://www.ecfs.eu/projects/ecfs-patient-registry/annual-reports). Taken together, these data support additional quality improvement (QI) in CF NBS to better understand the current screening practices in place, identify factors contributing to delays in diagnostic testing and identify barriers to receiving specialized CF multidisciplinary, clinical, and psychosocial care

Methods

Results

Discussion

Conclusion