Background
Pediatric oncology patients are at increased risk for invasive bacterial infection due to immunosuppression. The risk of such infection in the absence of severe neutropenia (absolute neutrophil count (ANC) ≥500/μl) is not well established and a validated prediction model for blood stream infection (BSI) risk offers clinical utility.
Methods
A six-site retrospective external validation was conducted using a previously published risk prediction model for BSI in febrile pediatric oncology patients without severe neutropenia, the Esbenshade/Vanderbilt (EsVan) model. A reduced model (EsVan2) excluding two less clinically reliable variables was also created using the initial EsVan model derivative cohort, and validated using all five external validation cohorts. One dataset was only used in sensitivity analyses due to missing some variables.
Results
From the five primary data sets, there were a total of 1197 febrile episodes and 76 episodes of bacteremia. The overall C-statistic for predicting bacteremia was 0.695 with a 0.50 calibration slope for the original model and 1.0 calibration slope when recalibration was applied to the model. The model performed better in predicting high-risk bacteremia (Gram negative or Staphylococcus aureus infection) versus BSI alone with a C-statistic of 0.801 and a calibration slope of 0.65. The EsVan2 model outperformed the EsVan model across datasets with a C-statistic 0.733 for predicting BSI and 0.841 for high-risk BSI.
Conclusions
This external validation shows that the EsVan and EsVan2 models are able to predict BSI across multiple performance sites and could assist in decision making in clinical practice once validated and implemented prospectively.