Retrospective study showed that blood sampling errors risked children's well‐being and safety in a Swedish paediatric tertiary care. - Hjelmgren, Henrik; Nilsson, Anna; Andersson‐Papadogiannakis, Nina; Ritzmo, Carina; Ygge, Britt‐Marie; Nordlund, Björn (Acta Paediatrica, 2019)