TABLE V.

Results of sensitivity analyses for key model assumption and parameter estimates

Scenario	Change in assumption or parameter estimate	icer for azacitidine versus ccrsa (mean: $/qaly)
Base-case result		86,182
A	Log-logistic curve fit for extrapolation of overall survival	82,647
B	Application of adverse event rates: annualized treatment-specific rates for patients on active treatment and annualized bsc rate for patients off active treatment	87,011
C	Application of adverse event rates: annualized treatment-specific rates for patients throughout the mds	90,116b
D	Utility value for aml with >30% blasts (range: 0.1–1.0)c
	0.1	86,314
	0.5	86,613
	1.0	86,126
E	Fixing utility scores for azacitidine and bsc at different longitudinal time points (from day 0, day 50, and day 106)
	From day 0	119,077
	From day 50	108,769
	From day 106	96,495
F	Adjusted azacitidine and bsc utility values	88,439
G	Wastage of azacitidine is consideredd	103,258

^aAll sensitivity analysis results showed that standard-dose chemotherapy was a cost-ineffective comparator relative to low-dose chemotherapy (ldc), and it was therefore excluded from the combined conventional care regimens. The weights of 68% for best supportive care and 32% for ldc from the aza-001 trial were applied to calculate the results of comparing the combined conventional care regimens to azacitidine.

^bIn this scenario, standard-dose chemotherapy was dominated when compared with azacitidine.

^cResults for only some of the utility values tested are reported.

^dThe average of 1.67 vials per injection was applied by assuming that half the wastage [(2 – 1.34) / 2] was lost, and the other half was made up through system efficiencies and new stability data¹⁹.

icer = incremental cost-effectiveness ratio; ccrs = conventional care regimens; qaly = quality-adjusted life year; bsc = best supportive care; mds = myelodysplastic syndrome; aml = acute myeloid leukemia.