Relationship between age group and percentage of patients experiencing ≥ grade 2 bleeding in all patients and stratified by disease treatment category. For all treatment groups, there was significantly higher incidence of bleeding in patients 0-5 and 6-12 years of age compared with those ≥ 19 years (*P < .001). In HSCT patients, all pediatric age cohorts had a higher incidence of bleeding than adults (*P < .04).