The real-world cost-effectiveness of adjuvant trastuzumab in HER-2/neu-positive early breast cancer in Taiwan

Figures & data

Figure 1. Markov model. Arrows indicate transitions. Arrows that curve back to the same state represent remains in the same state. DFS: Disease free survival. CHF: congestive heart failure.

Figure 2. Toranado analysis. EV, expect value of ICER for Trastuzmab

Table 1. Parameters data in sensitivity analysis.

Variable	Base-case value	Minimum value	Maximum value	Assumed distribution	Mean	SD	Sources
Transition probability
Trastuzumab gr.
DF to LR	0.02	0.016	0.037	Beta	0.026	0.014	[14,22]
DF to M	0.05	0.041	0.078	Beta	0.060	0.026	[15,21]
LR to M	0.03	0.031	0.078	Beta	0.055	0.034	[15,21]
M to D	0.22	0.220	0.295	Beta	0.258	0.053	[14,22]
Non-Trastuzumab
DF to LR	0.036	0.022	0.039	Beta	0.031	0.012	[15,21]
DF to M	0.079	0.079	0.091	Beta	0.085	0.0085	[15,21]
LR to M	0.078	0.078	0.091	Beta	0.085	0.0085	[15,21]
M to D	0.33	0.295	0.33	Beta	0.313	0.0245	[14,15]
Utility
Trastuzumab gr.
DF	0.749	0.696	0.97	Beta	0.833	0.194	[17,18]
LR to M	0.810	0.700	0.935	Beta	0.813	0.048	[19,20]
M to D	0.685	0.484	0.822	Beta	0.653	0.239	[15,20,22]
Non-Trastuzumab
DF	0.779	0.749	0.97	Beta	0.859	0.156	[16,17,22]
LR to M	0.810	0.700	0.935	Beta	0.818	0.166	[19,20]
M to D	0.685	0.484	0.822	Beta	0.653	0.239	[15,20,22]
Cost
Trastuzumab*
DF 1st year	27,256	19,736	35,724	Constant	27,256	2 550	Claim database
DF subsequence year	16,185	5634	31,104	Constant	16,185	10,842	Claim database
LR	40,115	40,115	40,115	Constant	40,115	–	Claim database
M	38 403	10,609	57,327	Constant	38,403	14,435	Claim database
Non-Trastuzumab
DF 1st year	16,241	13,287	19,378	Constant	16,241	2 495	Claim database
DF subsequence year	5 171	1533	8087	Constant	5 171	2 599	Claim database
LR	14,415	14,415	14,415	Constant	14,415	–	Claim database
M	18,856	7689	28,106	Constant	18,856	7 568	Claim database

All costs are in US dollars, exchange rate: 1.00 US$= NT$30.

DF, Disease free; LR, local recurrence; M, metastases; D, death; NT, non Trastuzumab.

* Cardiotoxicity treatment cost included.

Table 2. Cost-effectiveness analysis for lifetime model.

	Regimen
	Trastuzumab		Non-trastuzumab		Incremental cost		Incremental effectiveness		ICER (cost/QALY)
	Base	PSA	Base	PSA	Base	PSA	Base	PSA	Base	PSA
Direct medical cost (US$)	151,080	136,112	58,052	56,069	93,028	80,042
QALYs gained	4.984	4.431	3.353	3.375			1.631	1.056	57,037	75,798

PSA, Probability sensitivity analysis; 1US$= NT$30.

Figure 3. (a) Incremental cost-effectiveness plane. A sample of 10,000 results of the Markov Chain Monte Carlo simulation are plotted. The diagonal line represents a willingness-to-pay threshold of this study, where estimates below this line are cost-effective. (b) Cost-effectiveness acceptability curve. These show that probability that a specific treatment is cost-effective at a given willingness-to-pay threshold of US$67,060 (NT$2,213,145).