Context: All positive screening of newborns for cystic fibrosis using the dried blood spot 2-tiered immunoreactive trypsinogen/DNA method requires subsequent sweat chloride testing for confirmation. Obtaining an adequate volume of sweat to measure chloride is a challenge for many cystic fibrosis centers across the nation. The standard for patients older than 3 months is less than 5% quantity not sufficient (QNS) and for patients 3 months or younger is less than 10% QNS.
Objective: To set up a quality improvement (QI) program for sweat testing to improve QNS rates using the Wescor Macroduct (Wescor, Inc, Logan, Utah) method at Texas Children's Hospital's laboratory, Houston, Texas.
Design: Single-center study.
Results: Quantity not sufficient rates were evaluated for 4 months before and 8 months after implementation of the QI program for patients aged 3 months or younger and those older than 3 months. The QI program included changes in technician training, service, site of collection, mode of collection, weekly review, and forms to screen patients for medications that may alter sweat production. A marked improvement was observed in the rates of QNS, which declined considerably from 16.7% to 8.5% (≤3 months old) and from 9.3% to 2.2% (>3 months old) after implementation of the QI initiative in both age categories.
Conclusion: This report demonstrates the effectiveness of the QI program in significantly improving QNS rates in sweat chloride testing in a pediatric hospital.