Scatter plot of the disease severity score (y-axis) versus the tricuspid regurgitant jet velocity (m/s; x-axis) in the 210 subjects of the NIH–Pulmonary Hypertension Screening Study. For 29 subjects, the tricuspid regurgitant jet velocity could not be measured and was set equal to 1. The score of these 29 subjects ranges from 0.2 to 0.97; more than 75% of these subjects have a score above 0.5 and would be judged as severe. The 3 points highlighted by an ellipse represent a discordance in assessing the severity between our score and the tricuspid regurgitant jet velocity. While these patients have a tricuspid regurgitant jet velocity greater than 3 m/s (high risk of death), our model assigns them scores of 0.41, 0.46 (not at risk), and 0.60 (mild risk). One subject (score 0.41) had mitral valve insufficiency, subsequently treated surgically, so that the high tricuspid regurgitant jet velocity was due to cardiac disease. The second subject (score 0.46) had very severe pulmonary hypertension associated with very severe obstructive sleep apnea requiring tracheostomy. The third subject (score 0.6) had undergone apparently successful nonmyeloablative bone marrow transplantation since enrollment. She appeared to have typical sickle cell disease–associated pulmonary hypertension but was on chronic transfusion at the time of enrollment.