The purpose of this study is to understand physician treatment decisions in selecting specific second line treatments in pediatric ITP and to determine the effectiveness of different second line ITP treatments. Eligible patients are those ages 1-18 years who are starting on a new second line treatment for ITP, defined as any treatment other than IVIG, steroids, anti-D globulin, or aminocaproic acid. Enrolled patients remain on the study for approximately one year.

The purpose of this observational study is to model factors that determine physician treatment decisions in selecting specific second line agents in pediatric ITP and to determine the comparative effectiveness of second line ITP treatments by bleeding measures, platelet counts, and patient reported outcome measures. This prospective observational, longitudinal, multicenter cohort study will aim to collect routine clinical care data, quality of life information from patients, and decision making data from clinicians at enrollment and at regular clinical intervals for at least one year. The primary and secondary objectives are as follows:

Primary Objectives:

1. To model factors that determine physician treatment decisions in selecting specific second line agents in pediatric ITP.
2. To assess patient reported outcomes with relation to specific second line pediatric ITP therapies.
3. To determine the comparative effectiveness of second line ITP treatments in terms of bleeding and platelet counts.

Secondary Objectives:

1. To describe phenotypic variation among patients with refractory ITP;
2. To assess side effects and complications related to specific treatments for refractory ITP;
3. To describe monitoring and follow up practices among pediatric hematologists with each second line agent;
4. To weight factors that physicians use when deciding to treat pediatric ITP patients with second line agents;
5. To determine whether physician perception of patient quality of life correlates with patient derived quality of life measures;
6. To measure the correlation between the ITP Bleeding Scale and the Bleeding Assessment Tool in refractory pediatric ITP patients.

Inclusion Criteria:

• Immune Thrombocytopenia or Evans Syndrome
• Ages > 12 months to <18 years
• Starting a new second line therapy as defined as any therapy except IVIG, steroids, anti-D globulin, or aminocaproic acid
• Starting a single agent/monotherapy

Exclusion Criteria:

• Evans Syndrome with a history of or current evidence of autoimmune hemolytic anemia
• Unwillingness to be followed for 1 year
• Physician providing care is unwilling to participate
• Patient is starting multiple second line agents simultaneously

Pediatric refractory ITP patients starting on a new second line therapy