Written by Clay Smith
Sensitivity for Boston and Philadelphia criteria to detect invasive bacterial infection (IBI) in infants 29-60 days old was 62.7% and 71.7%, respectively. That’s pretty awful.
Why does this matter?
Risk stratifying infants 29-60 days old is tough. When infants met all low-risk Boston criteria in the original study, 5.4% had serious bacterial infection (SBI) when culture results came back. Philadelphia criteria had 98% sensitivity in its initial study. Might these older clinical decision tools help us?
A tale of two cities
This was a pre-planned secondary analysis of a retrospective, cross sectional HSV study from 2005 to 2013 with over 8,000 infants 29-60 days to determine the diagnostic accuracy of the Boston and Philadelphia criteria to detect IBI. They had to modify the original criteria to include both spun and unspun urine microscopy with bacteria on Gram stain or ≥10 WBCs, and in cases without urine microscopy, they counted trace to 3+ leukocyte esterase as positive. There were 264 patients (2.4%) with IBI; 71 (0.6%) with bacterial meningitis; 193 (1.8%) with bacteremia. Overall, sensitivity for IBI was 62.7 (95%CI 55.9 to 69.3) for Boston and 71.7 (95%CI 65.2 to 77.6) for Philadelphia. Sensitivity for SBI was only slightly better: Boston 79.4 (76.7 to 81.9); Philadelphia 86.2 (83.9 to 88.3). These criteria would have misclassified 25-33% of infants with a final diagnosis of bacterial meningitis as low risk. That’s not good. Both Boston and Philadelphia require CSF to be obtained in all patients, and the diagnostic accuracy of both was pretty awful. It is time for newer tools, such as step-by-step and PECARN, to overtake these outmoded criteria.
Performance of the Modified Boston and Philadelphia Criteria for Invasive Bacterial Infections. Pediatrics. 2020 Apr;145(4). pii: e20193538. doi: 10.1542/peds.2019-3538. Epub 2020 Mar 23.
Open in Read by QxMD