TABLE 4.

Key inputs for the cost-effectiveness model.

Parameter	Value	Low	High	Distribution	Source
Cost (US$)
Sintilimab/1000 mg	167.40	133.92	200.88	Gamma	Negotiation price
Cisplatin/50 mg	11.78	9.42	14.14	Gamma	Local charge
Paclitaxel/30 mg	11.44	9.15	13.73	Gamma	Local charge
5-Fluorouracil/250 mg	9.61	7.69	11.53	Gamma	Local charge
Docetaxel/20 mg	27.90	22.32	33.48	Gamma	Local charge
Cost of BSC	117	32.3	322.6	Gamma	Zhang et al. (2020)
Cost of the follow-up	52.80	36.96	68.64	Gamma	Shi et al. (2021)
Chest enhanced CT	134.37	107.50	161.24	Gamma	Shi et al. (2021)
Abdominal enhanced CT	134.37	107.50	161.24	Gamma	Du et al. (2022)
Cost of the laboratory test	90.32	72.26	108.38	Gamma	Meng-xue et al. (2022)
Other cost
Anti-tumor drug dispensing fees	4.01
Cost of IV	2.78
Hospitalization expense/day	19.86
Cost of SAEs
Anemia	669.45	535.56	803.34	Gamma	Du et al. (2022)
Decrease in the white blood cell count	206.72	165.376	248.06	Gamma	Du et al. (2022)
Decrease in the neutrophil count	544.19	435.35	613.43	Gamma	Du et al. (2022)
Asthenia	115.00	92.00	138.00	Gamma	Yang et al. (2021)
Increase in blood pressure	1.35	1.08	1.62	Gamma	Wen et al. (2021)
Utility
PFS	0.741	0.593	0.889	Beta	Wu et al. (2012); Zhang et al. (2020)
PD	0.581	0.465	0.697	Beta	Wu et al. (2012); Zhang et al. (2020)
Disutility due to grade 1 and 2 AEs	0.01	0.008	0.02	Beta	Amdahl et al. (2016); Su et al. (2021)
Disutility due to grade 3 and 4 AEs	0.16	0.11	0.204	Beta	Amdahl et al. (2016); Su et al. (2021)
Accounting rate	5%	0%	8%	Fix

Abbreviation: BSC, best support care; SAEs, serious adverse events (≥ grade 3); IV, intravenous injection; PFS, progression-free survival; PD, progression disease; CT, computerized tomography