to define disease severity (0, least severe to 1, most severe) as the risk of death within 5 years [129]. This initial network was validated in 140 patients whose disease severity was assessed by expert clinicians and 210 adults where severity was also assessed by the echocardiographic diagnosis of pulmonary hypertension and death. We implemented a version of this calculator of disease severity on the internet using Java (http://www.bu.edu/sickle-cell/downloads/Projects/). Although Bayesian networks are more difficult to generate and more challenging to communicate than traditional regression models, they are slowly becoming more accepted in the genetic community [130,131].
