Clinical practices for intermediate sweat tests following abnormal cystic fibrosis newborn screens

BackgroundNewborn screening (NBS) for cystic fibrosis (CF) has become standard practice in many countries. Consequently, the prevalence of infants with intermediate sweat test results has increased. This study examined clinical practices in the United States (US) related to intermediate sweat test results subsequent to NBS.MethodsRespondents from 77 (47% response rate) US CF centers completed telephone surveys documenting clinical practices related to intermediate sweat chloride levels (30–59 mmol/L) following abnormal NBS.ResultsThirty percent of centers followed CF Foundation guidelines for classifying intermediate results. There was much variability in sweat testing procedures, diagnostic labels, additional diagnostics, addressing prognosis, and services offered to parents. CF center staff identified a need for resources to better address the uncertainty associated with intermediate results.ConclusionResults suggest the need for education regarding current guidelines and consensus regarding the nomenclature and services offered to families of newborns with intermediate sweat test results.