Validations in independent patient groups. (A,B) Validation in patients from the Boston Medical Center. (A) Distribution of severity score (x-axis) for groups of adults (aged ≥ 18 years) whose clinical status was assessed as mild, intermediate, or severe. (B) Distribution of severity score (x-axis) for the pediatric groups (aged < 18 years) whose clinical status was assessed as mild/intermediate (bottom) and severe. (C,D) Validation in patients from the NIH. (C) Distribution of severity score (x-axis) for patients whose clinical status was determined as mild/intermediate (bottom box plot) and severe (top box plot). (D) Distribution of severity score of the 19 subjects who died during the follow-up (top 3 box plots) and the 191 subjects who survived the follow-up (bottom 3 box plots), grouped as follows: no pulmonary hypertension (tricuspid regurgitant jet velocity ≤ 2.5 m/s); mild pulmonary hypertension (2.5 < tricuspid regurgitant jet velocity < 3 m/s); severe pulmonary hypertension (tricuspid regurgitant jet velocity ≥ 3.0 m/s).