RT Journal Article SR Electronic T1 Febrile young infants with abnormal urine dipstick at low risk of invasive bacterial infection JF Archives of Disease in Childhood JO Arch Dis Child FD BMJ Publishing Group Ltd and Royal College of Paediatrics and Child Health SP 758 OP 763 DO 10.1136/archdischild-2020-320468 VO 106 IS 8 A1 Velasco, Roberto A1 Lejarzegi, Ainara A1 Gomez, Borja A1 de la Torre, Mercedes A1 Duran, Isabel A1 Camara, Amaia A1 de la Rosa, Daniel A1 Manzano, Sergio A1 Rodriguez, Jose A1 González, Andres A1 Lopes, Anne-Aurelie A1 Rivas, Aristides A1 Martinez, Isabel A1 Angelats, Carlos Miguel A1 Moya, Sandra A1 Corral, Sonia A1 Alonso, Juan A1 del Rio, Patricia A1 Sancho, Elena A1 Ruiz del Olmo, Ignacio A1 Nieto, Inmaculada A1 Vega, Beatriz A1 Mintegi, Santiago YR 2021 UL http://adc.bmj.com/content/106/8/758.abstract AB Objectives To develop and validate a prediction rule to identify well-appearing febrile infants aged ≤90 days with an abnormal urine dipstick at low risk of invasive bacterial infections (IBIs, bacteraemia or bacterial meningitis).Design Ambispective, multicentre study.Setting The derivation set in a single paediatric emergency department (ED) between 2003 and 2017. The validation set in 21 European EDs between December 2017 and November 2019.Patients Two sets of well-appearing febrile infants aged ≤90 days with an abnormal urine dipstick (either leucocyte esterase and/or nitrite positive test).Main outcome Prevalence of IBI in low-risk infants according to the RISeuP score.Results We included 662 infants in the derivation set (IBI rate:5.2%). After logistic regression, we developed a score (RISeuP score) including age (≤15 days old), serum procalcitonin (≥0.6 ng/mL) and C reactive protein (≥20 mg/L) as risk factors. The absence of any risk factor had a sensitivity of 96.0% (95% CI 80.5% to 99.3%), a negative predictive value of 99.4% (95% CI 96.4% to 99.9%) and a specificity of 32.9% (95% CI 28.8% to 37.3%) for ruling out an IBI. Applying it in the 449 infants of the validation set (IBI rate 4.9%), sensitivity, negative predictive value and specificity were 100% (95% CI 87.1% to 100%), 100% (95% CI 97.3% to 100%) and 29.7% (95% CI 25.8% to 33.8%), respectively.Conclusion This prediction rule accurately identified well-appearing febrile infants aged ≤90 days with an abnormal urine dipstick at low risk of IBI. This score can be used to guide initial clinical decision-making in these patients, selecting infants suitable for an outpatient management.Data are available upon reasonable request.