BackgroundSinusoidal obstructive syndrome is a potentially fatal complication following hematopoietic cell transplantation, high-intensity chemotherapies and increasingly seen with calicheamicin based leukaemia therapies. Paediatric specific European Society for Blood and Marrow Transplantation (pEBMT) diagnostic criteria have demonstrated benefit in single centre studies compared to historic criteria. Yet, the extent to which they have been universally implemented remains unclear. MethodsWe conducted a retrospective multi-centre study to examine the potential impact of the Baltimore, modified Seattle and pEBMT criteria on the incidence, severity, and outcomes of sinusoidal obstructive syndrome among paediatric hematopoietic cell transplantation patients. FindingsThe incidence of sinusoidal obstructive syndrome in this cohort (n=488) was higher by pEBMT (21·5%) versus historic modified Seattle (15·6%) and Baltimore (7·0%) criteria (p<0·001). Application of pEBMT criteria identified 44 patients who were not previously diagnosed with sinusoidal obstructive syndrome. Overall, 70·5% of all patients diagnosed with sinusoidal obstructive syndrome ultimately developed severe/very severe disease and almost half of diagnosed patients required critical care support. Overall survival was significantly lower in patients who were diagnosed with sinusoidal obstructive syndrome versus those who were not. InterpretationTaken together, pEBMT criteria may be a sensitive method for prompter diagnosis of patients who subsequently develop severe/very severe sinusoidal obstructive syndrome. To our knowledge, this is the first multi-centre study in the United States (US) to demonstrate that pEBMT guidelines are associated with earlier detection of sinusoidal obstructive syndrome. Since early initiation of definitive treatment for sinusoidal obstructive syndrome has been associated with improved survival in paediatric patients and implementation of pEBMT criteria appears feasible in the US, universal adoption should facilitate prompter diagnosis and lead to improved outcomes of children with sinusoidal obstructive syndrome.Funding: None