The incidence and clinical burden of immune thrombocytopenia in pediatric patients in the United States

Abstract

Immune thrombocytopenia (ITP) is the most common bleeding disorder diagnosed in children. Characterized by low platelet counts, it leads to reduced clotting abilities and an increased tendency to bleed. The disorder in children is often self-limiting. However, approximately 25% of children develop persistent or chronic ITP, and bleeding associated with thrombocytopenia can be life-threatening. The current incidence of ITP in the US and the characterization of the illness among children being managed in routine clinical practice are sparsely reported. This retrospective cohort study leveraged a large US-based commercial claims database to estimate the current incidence of pediatric ITP, the uptake of ITP treatments, and the occurrence of clinical outcomes of interest. Overall, the incidence of ITP in patients <18 years was 8.8 (95% confidence interval; 8.5–9.1) per 100,000 person-years from 2011 to 2016. Within two years of ITP onset, >31% of patients received IVIg and/or oral corticosteroids. Other ITP therapies were less common. During this same time period, 50% had at least one bleeding event (ecchymosis, epistaxis, gastrointestinal hemorrhage, etc.), 24% were hospitalized for a bleeding event, and 62% had at least one ITP-related hospitalization. The majority of patients experiencing these events did so within the first month following ITP onset. Our findings confirm the rarity of ITP and relatively low likelihood of chronic disease in young patients, but reveal that for a significant proportion of patients in the newly diagnosed phase, clinical consequences can be serious. Further study of improved treatment methods throughout the disease course is warranted.

Keywords:

• Bleeding event
• immune thrombocytopenia
• incidence rate
• ITP
• pediatric patients

Author contribution

Jaime Shaw contributed study concept and design, analysis and interpretation of data, and drafting of manuscript; Karynsa Kilpatrick contributed study concept and design, analysis, and interpretation of data, drafting, and critical revision of manuscript for important intellectual content; Melissa Eisen contributed study concept and design, interpretation of data, and critical revision of manuscript for important intellectual content; and Michael Tarantino contributed to the study concept and design, interpretation of data, and critical revision of manuscript for important intellectual content.

Conflicts of interest

Jaime Shaw, Karynsa Kilpatrick, and Melissa Eisen are Amgen employees and have stock ownership in Amgen Inc.; and Michael Tarantino is and has been a clinical investigator for Amgen and trials.

Supplementary material

Supplemental data for this article can be accessed here.

Additional information

Funding

This study was funded by Amgen, Inc. Amgen authors were supported by their annual salaries.