Delegated staff should be chosen based upon clinical skill in clinical assessment (e.g., hemophilia physical therapist, oncology nurse) and ability of this individual to remain blinded to treatment arm (i.e. duration of therapy)-hence, not a clinician involved in the direct care of thrombosis patients. This individual must complete video-based training on standardized PTS assessment, complete the post-training quiz and send the completed quiz to the Clinical Coordinating Center for scoring. A score of 80% must be achieved prior to certification by the Coordinating Center for PTS assessment in the trial.