TABLE 1. Estimates for Clinical Probabilities and Quality of Life Measures.

For clinical probabilities, base case estimates were extracted from published pediatric studies with the largest sample size. The range of estimates was based on all identified studies in the pediatric literature, or from adult literature if pediatric-specific data were not available. For utility estimates, the range is the base case estimate ± 0.2.

	Base case estimate	Range	References or sources
CLINICAL PARAMETERS
Probability of severe SCD
Hydroxyurea (HU)	27%	20-45%	[2, 18-22]
Chronic transfusion (CTX)	15%	6-15%	[4, 23, 24]
Probability of mortality
No treatment	3%	1-40%	[25, 26]
Hydroxyurea	0%	0-10%	[14, 27]
Chronic transfusion	1.1%	1-50%	[11]
Stem Cell Transplant (SCT)	6%	1-10%	[3, 28-30]
Probability of iron overload with CTX	95%	0-100%	[31, 32]
Probability of graft failure with SCT	10%	10-18%	[3, 28-30]
Probability of chronic GVHD with SCT	3.8%	7.7-22%	[3, 28-30]
QUALITY OF LIFE MEASURES (UTILITIES)
Alive, no treatment, severe disease	0.7	0.5-0.9	[8, 10]
Alive, on HU, severe disease	0.65	0.45-0.85	[8, 10]
Alive, on HU, no severe disease	0.85	0.65-1	[8, 10]
Alive, on CTX, severe disease, iron overload	0.55	0.35-0.75	[8, 10]
Alive, on CTX, no severe disease, iron overload	0.75	0.55-0.95	[8, 10]
Alive, on CTX, severe disease, no iron overload	0.60	0.40-0.80	[8, 10]
Alive, on CTX, no severe disease, no iron overload	0.80	0.60-1	[8, 10]
Alive, SCT, graft failure	0.55	0.35-0.75	[8, 10]
Alive, SCT, no graft failure, chronic GVHD	0.65	0.45-0.85	[8, 10]
Alive, SCT, no graft failure, no chronic GVHD	0.95	0.75-1	[8, 10]
Death	0	---	[8, 10]