A network model to predict the risk of death in sickle cell disease

Abstract

Modeling the complexity of sickle cell disease pathophysiology and severity is difficult. Using data from 3380 patients accounting for all common genotypes of sickle cell disease, Bayesian network modeling of 25 clinical events and laboratory tests was used to estimate sickle cell disease severity, which was represented as a score predicting the risk of death within 5 years. The reliability of the model was supported by analysis of 2 independent patient groups. In 1 group, the severity score was related to disease severity based on the opinion of expert clinicians. In the other group, the severity score was related to the presence and severity of pulmonary hypertension and the risk of death. Along with previously known risk factors for mortality, like renal insufficiency and leukocytosis, the network identified laboratory markers of the severity of hemolytic anemia and its associated clinical events as contributing risk factors. This model can be used to compute a personalized disease severity score allowing therapeutic decisions to be made according to the prognosis. The severity score could serve as an estimate of overall disease severity in genotypephenotype association studies, and the model provides an additional method to study the complex pathophysiology of sickle cell disease. (Blood. 2007;110: 2727-2735)

Traffic Light: prognosis-based eligibility for clinical trials of hematopoietic SCT in adults with sickle cell anemia

“…The BNM incorporates 25 historical clinical events and laboratory results to estimate SCA mortality risk. 25 Data collection and definitions. Well-annotated demographic, historical, clinical and laboratory data were available from both walk-PHaSST and CSSCD, as defined in each study.…”

“…20 By convention, macroalbuminuria is 4300 mg of urinary albumin per g creatinine (mg/g). The BNM severity score was calculated using an on-line Java-enabled program, as per Sebastiani et al 25,29 , in which elevated age was 435 years, an elevated LDH was 4600 IU/L and an elevated WBC was 413.5 × 10 3 cells/μL. A BNM Severity score of 40.95 'units' (range 0 to 1) was considered high risk in our analysis.…”

Development and validation of a pediatric severity index for sickle cell patients

“…All patients in the study were classified according to severity by a subjective expert classification and by the ''SCD Assessment Instrument'' (SCDAI) described by Day [8] and we calculated the risk of death score published by Sebastiani [14].…”

“…The risk of death score consists of 16 items (both clinical events and laboratory tests) predicting the risk of death within 5 years. The predictive value of the death risk score was validated in two unrelated sets of patients [14].…”

Chronic Liver Disease among Adult Patients with Sickle Cell Anemia in Steady State in Ile-Ife, Nigeria

“…Persistent hepatomegaly is one of the established markers of disease severity in SCA patients [25,26] . Olatunji et al [27] in Ilorin, Nigeria also established that persistent hepatomegaly is an index of disease severity in patients with sickle cell anemia.…”