Data on the epidemiological burden and comorbidities associated with pulmonary embolism (PE) in children and adolescents is sparse. We aimed to describe the burden of acute PE in children by estimating indicators of incidence and mortality as well as the prevalence of key comorbidities in hospitalized children with (vs. without) PE.

We did a patient-level analysis of the United States Kids' Inpatient Database (KID), including patients aged 0 to 19, cumulatively for the years 2016 and 2019. PE was defined by the ICD-10 Code I26. We calculated the annualized, nationwide, age-sex-specific incidence rate, mortality rate, case mortality rate, and proportionate mortality rate. Additionally, we studied the prevalence of 120 clinically selected disorders in children with vs. without acute PE.

Acute PE was recorded in 5,733 cases (58.6% female). A total of 244 (4.3%) patients were aged 0, 214 (3.7%) aged 1-4, 206 (3.6%) aged 5-9, 677 (11.8%) aged 10-14, and 4,392 (76.5%) aged 15-19 years. The incidence rate of PE shows a J-shape curve increasing with increasing age. Proportional mortality rate paralleled the incidence rate peaking at 9.5 (95% CI: 7.3-12.3) deaths per 1,000 deaths for girls and 5.0 (4.0-6.2) deaths per 1,000 deaths for boys aged 15-19 years. In contrast, case mortality rate decreased from 33% (95% CI: 24.8-42.4) among girls and 15.9% (95% CI: 10.8-23) among boys in the first year of age to 2.1% (95% CI: 1.6-2.7) among girls and 4.5% (95% CI: 3.6-5.6) among boys aged 15-19. Table 1 presents key age-sex stratified epidemiologic indicators. The highest absolute prevalence difference (APD) between those with vs. without PE was found for venous thrombosis (APD: 31.8%, 95% CI: 30.6-33), followed by metabolic disorders (APD: 15.2%, 95% CI: 14-16.5) and obesity (APD: 14.7%, 95% CI: 13.7-15.8). Figure 1 presents an overview of the APD of clinically selected disorders in patients with vs. without PE.

This comprehensive overview shows that the burden of PE among children and adolescents is substantial, but with considerable variation across age-sex classes and heterogeneity in terms of different comorbidities.