Outcome measures in interventional trials for prevention or treatment of venous thrombosis in the pediatric population.

Determining clinically relevant outcomes are one of the key issues in the design of clinical trials. Recently, a working group from the Perinatal and Pediatric Subcommittee of the Scientific and Standardization Committee of the International Society of Thrombosis and Haemostasis published a position article defining outcomes in interventional trials for prevention and treatment of deep vein thrombosis (DVT) in children. For these studies the primary efficacy outcomes are DVT and the primary safety outcomes are bleeding. The exact definitions for these outcomes are included in this review article. This article expands on these recommendations by summarizing and reviewing the current literature in pediatric anticoagulation studies; discussing the relationship of choice of outcomes to specific clinical trial design; providing a more detailed discussion on the rationale for the defined outcomes in pediatric anticoagulation trials, as well as a detailed examination of secondary and tertiary outcomes. With a growing interest in multicenter, multinational pediatric anticoagulation clinical trials, establishment of standardized outcome measures that are applied uniformly over all studies is critically important. Agreement from the international academic community on these outcomes is an important step in assuring well-designed clinical trials, which are implemented to optimize the prevention and treatment of DVT in children.