TABLE 2. Threshold Values Identified in Sensitivity Analysis.

We performed one-way sensitivity analysis, in which the value of each clinical probability and quality of life estimate was varied one at a time over a wide range of values. In the majority of cases, estimates had to be varied outside of the plausible range for an intervention other than stem cell transplant to be the preferred strategy.

	Plausible range based on published literature	Results
CLINICAL PARAMETERS
Probability of severe SCD
Hydroxyurea (HU)	20-45%	If probability of severe disease <1%, HU preferred over SCT If probability of severe disease >60%, CTX preferred over HU
Chronic transfusion (CTX)	6-15%	If probability of severe disease >43%, no treatment preferred
Probability of mortality
Hydroxyurea	0-10%	SCT always preferred
Chronic transfusion	1-50%	SCT always preferred
Stem Cell Transplant (SCT)	1-10%	If SCT mortality ≥11%, HU becomes preferred strategy
Probability of iron overload with CTX	0-100%	SCT always preferred
Probability of graft failure with SCT	10-18%	If probability of graft failure ≥23%, HU becomes preferred strategy
Probability of chronic GVHD with SCT	7.7-14%	If probability of GVHD ≥23%, HU becomes preferred strategy
QUALITY OF LIFE MEASURES (UTILITIES)
Alive, on HU, severe disease	0.45-0.85	If utility >0.843, HU becomes preferred strategy
Alive, on HU, no severe disease	0.65-1	If utility >0.914, HU becomes preferred strategy
Alive, on CTX, severe disease, iron overload	0.35-0.75	SCT always preferred
Alive, on CTX, no severe disease, iron overload	0.55-0.95	SCT always preferred
Alive, on CTX, severe disease, no iron overload	0.40-0.80	SCT always preferred
Alive, on CTX, no severe disease, no iron overload	0.60-1	SCT always preferred
Alive, SCT, graft failure	0.35-0.75	If utility is <0.04, SCT no longer preferred
Alive, SCT, no graft failure, chronic GVHD	0.45-0.85	SCT always preferred
Alive, SCT, no graft failure, no chronic GVHD	0.75-1	If utility is <0.89, HU becomes preferred strategy