<p><strong>BACKGROUND: </strong>Treatment of infants with acute leukemia remains challenging, especially for acute lymphocytic leukemia (ALL). Infants have shown markedly higher rates of induction mortality compared with noninfants. There are limited data on presentation acuity and supportive care utilization in this age group.</p>

<p><strong>METHODS: </strong>In retrospective analyses of patients treated for new onset ALL or acute myeloid leukemia (AML) at pediatric hospitals contributing to the Pediatric Health Information System, we compared presentation acuity, induction mortality, and resource utilization in infants relative to noninfants less than 10&nbsp;years at diagnosis.</p>

<p><strong>RESULTS: </strong>Analyses included 10&nbsp;359 children with ALL (405 infants, 9954 noninfants) and 871 AML (189 infants, 682 noninfants). Infants were more likely to present with multisystem organ failure compared to noninfants for both ALL (12% and 1%, PR&nbsp;=&nbsp;10.8, 95% CI: 7.4, 15.7) and AML (6% vs. 3%; PR&nbsp;=&nbsp;2.0, 95% CI: 1.0, 3.7). Infants with ALL had higher induction mortality compared to noninfants, even after accounting for differences in anthracycline exposure and presentation acuity (2.7% vs. 0.5%, HR&nbsp;=&nbsp;2.1, 95% CI: 1.0, 4.8). Conversely, infants and noninfants with AML had similar rates of induction mortality (3.2% vs. 2.1%, HR&nbsp;=&nbsp;1.2, 95% CI: 0.3, 3.9), which were comparable to rates among infants with ALL. Infants with ALL and AML had greater requirements for blood products, diuretics, supplemental oxygen, and ventilation during induction relative to noninfants.</p>

<p><strong>CONCLUSIONS: </strong>Infants with leukemia present with higher acuity compared with noninfants. Induction mortality and supportive care requirements for infants with ALL were similar to all children with AML, and significantly higher than those for noninfants with ALL.</p>

<p>Despite the importance of adverse event (AE) reporting, AEs are under-reported on clinical trials. We hypothesized that electronic medical record (EMR) data can ascertain laboratory-based AEs more accurately than those ascertained manually. EMR data on 12 AEs for patients enrolled on two Children's Oncology Group (COG) trials at one institution were extracted, processed and graded. When compared to gold standard chart data, COG AE report sensitivity and positive predictive values (PPV) were 0-21·1% and 20-100%, respectively. EMR sensitivity and PPV were &gt;98·2% for all AEs. These results demonstrate that EMR-based AE ascertainment and grading substantially improves laboratory AE reporting accuracy.</p>