Expanded Screening of One Million Swedish Babies with R4S and CLIR for Post-Analytical Evaluation of Data

• Main Authors: Lene Sörensen, Ulrika von Döbeln, Henrik Åhlman, Annika Ohlsson, Martin Engvall, Karin Naess, Carolina Backman-Johansson, Yvonne Nordqvist, Anna Wedell, Rolf H. Zetterström
• Format: Article
• Language: English
• Published: MDPI AG 2020-05-01
• Series: International Journal of Neonatal Screening
• Subjects: Newborn screening; post-analytical evaluation; Collaborative Laboratory Integrated Reports (CLIR); tandem mass spectrometry; expanded screening; dried blood spots (DBS)
• Online Access: https://www.mdpi.com/2409-515X/6/2/42

Sweden has one neonatal screening laboratory, receiving 115 to 120 thousand samples per year. Among the one million babies screened by tandem mass spectrometry from November 2010 until July 2019, a total of 665 babies were recalled and 311 verified as having one of the diseases screened for with this methodology, giving a positive predictive value (PPV) of 47% and an incidence of 1:3200. The PPV was high (41%) already in the first year after start of screening, thanks to the availability of the collaborative project Region 4 Stork database. The PPV is presently 58%. This improvement was achieved by the implementation of second-tier analyses in the screening for methylmalonic aciduria, propionic aciduria, isovaleric aciduria, and homocystinuria, and the employment of various post analytical tools of the Region 4 Stork, and its successor the collaborative laboratory integrated reports.