Table 1 Model parameters: key clinical and health preference data

Clinical data

Weibull survival model for OS of serplulimab plus CF

Overall patients

Scale = 0.02617, Shape = 1.16846

-

-

(19)

-

Patients with PD-L1 expression level of 1 ≤ CPS < 10

Scale = 0.029888, Shape = 1.176584

-

-

-

Patients with PD-L1 CPS ≥ 10

Scale = 0.016952, Shape = 1.254789

-

-

-

Weibull survival model for PFS of serplulimab plus CF

Overall patients

Scale = 0.10927, Shape = 0.97361

-

-

(19)

-

Patients with PD-L1 expression level of 1 ≤ CPS < 10

Scale = 0.10943, Shape = 1.05893

-

-

-

Patients with PD-L1 CPS ≥ 10

Scale = 0.087778, Shape = 0.989156

-

-

-

Weibull survival model for OS of placebo plus CF

Overall patients

Scale = 0.020542, Shape = 1.404457

-

-

(19)

-

Patients with PD-L1 expression level of 1 ≤ CPS < 10

Scale = 0.0127079, Shape = 1.6243877

-

-

-

Patients with PD-L1 CPS ≥ 10

Scale = 0.030741, Shape = 1.212235

-

-

-

Weibull survival model for PFS of placebo plus CF

Overall patients

Scale = 0.0931, Shape = 1.32774

-

-

(19)

-

Patients with PD-L1 expression level of 1 ≤ CPS < 10

Scale = 0.06808, Shape = 1.50072

-

-

-

Patients with PD-L1 CPS ≥ 10

Scale = 0.06808, Shape = 1.524542

-

-

-

Risk for main AEs in serplulimab plus CF group

Anemia

0.180

0.144

0.216

(19)

Beta

Hyponatremia

0.050

0.040

0.060

(19)

Beta

Neutrophil count decreased

0.190

0.152

0.228

(19)

Beta

White blood cell count decreased

0.110

0.088

0.132

(19)

Beta

Risk for main AEs in placebo plus CF group

Anemia

0.200

0.160

0.240

(19)

Beta

Neutrophil count decreased

0.170

0.136

0.204

(19)

Beta

White blood cell count decreased

0.070

0.056

0.084

(19)

Beta

Proportion of receiving active second-line treatment

Serplulimab plus CF

0.520

0.416

0.624

(19)

Beta

CF

0.380

0.304

0.456

(19)

Beta

Utility and disutility

Utility of PFS

0.680

0.544

0.816

(21)

Beta

Utility of PD

0.420

0.336

0.504

(21)

Beta

Disutility of anemia

0.074

0.059

0.089

(21)

Beta

Disutility of neutrophil count decreased

0.090

0.072

0.108

(21)

Beta

Disutility of white blood cell count decreased

0.090

0.072

0.108

(21)

Beta

Disutility of hyponatremia

0

-

-

(21)

-

Body weight (kilogram)

65

52

78

(19, 20)

Normal

Body surface area (meters²)

1.72

1.38

2.06

(19, 20)

Normal

Discount rate

0.05

0

0.08

(21, 24)

Uniform