Cost-effectiveness of sponge cytology test vs endoscopy for esophageal squamous cell carcinoma screening in high-risk areas

Table 1 Model input

Parameter	Base case	Range1	Distribution2	Ref.
Prevalence (%)3				Zeng et al[14], 2020; Xia et al[18], 2021; Chen et al[37], 2017; and Xia et al[38], 2022
mD	2.04	1.02-4.52	Triangular (0.0102, 0.0204, 0.0452)
MD	0.22	0.11-0.59	Triangular (0.0011, 0.0022, 0.0059)
SD/CIS	0.12	0.06-0.38	Triangular (0.0006, 0.0012, 0.0038)
EEC	0.05	0.03-0.10	Triangular (0.0003, 0.0005, 0.0010)
AEC	0.02	0.01-0.04	Triangular (0.0001, 0.0002, 0.0004)
Annual state transition rate4				Xia et al[18], 2021; Chen et al[37], 2017; and Xia et al[38], 2022
Healthy to mD	0.0120	± 50%	Triangular (0.006, 0.012, 0.018)
mD to healthy	0.0500	± 50%	Triangular (0.025, 0.05, 0.075)
mD to MD	0.0500	± 50%	Triangular (0.025, 0.05, 0.075)
MD to mD	0.0800	± 50%	Triangular (0.04, 0.08, 0.12)
MD to SD/CIS	0.1200	± 50%	Triangular (0.06, 0.12, 0.18)
SD/CIS to MD	Age-specific
SD/CIS to EEC
EEC to AEC
PT-SD/CIS to SD/CIS	0.0050	± 50%	Triangular (0.0025, 0.005, 0.0075)
PT-EEC to EEC	0.0500	± 50%	Triangular (0.025, 0.05, 0.075)
PT-EEC to AEC	0.1000	± 50%	Triangular (0.05, 0.10, 0.15)
PT-AEC to AEC	0.2304	± 50%	Triangular (0.115, 0.23, 0.345)
Participation rate				Gao et al[8], 2023; Xia et al[18], 2021; Chen et al[37], 2017; and Xia et al[38], 2022
Endoscopy screening	0.3352	± 50%	Triangular (0.30, 0.34, 0.67)
Sponge cytology screening	0.56	± 50%	Triangular (0.50, 0.56, 0.80)
Endoscopy after sponge cytology test	0.75	± 50%	Triangular (0.40, 0.75, 0.90)
Probability of receiving treatment3				Xia et al[18], 2021; Chen et al[37], 2017; and Xia et al[38], 2022
SD/CI	0.7458	0.5625-0.9654	Beta (20.75, 7.07)
EEC	0.9405	0.7149-1.0000	Beta (5.13, 0.32)
AEC	0.9643	0.8393-1.0000	Beta (11.08, 0.41)
Probability of symptomatic detection				Xia et al[18], 2021; Chen et al[37], 2017; and Xia et al[38], 2022
SD/CIS	0.01	0.005-0.02	Triangular (0.005, 0.01, 0.02)
EEC	0.20	0.10-0.40	Triangular (0.10, 0.20, 0.40)
AEC	0.70	0.56-0.90	Triangular (0.56, 0.70, 0.90)
Cost (USD)
Endoscopic test	74.31	± 50%	Triangular (50.36, 74.31, 108.69)	Xia et al[18], 2021; Li et al[19], 2019; Chen et al[37], 2017; and Xia et al[38], 2022
Sponge cytology test	35	± 50%	Triangular (17.5, 35, 52.5)	Estimated
Endoscopic complications	119.61	± 50%	Gamma (9.75, 0.08)	Xia et al[18], 2021; Chen et al[37], 2017; and Xia et al[38], 2022
Initial treatment				Xia et al[18], 2021; Chen et al[37], 2017; and Xia et al[38], 2022
SD/CIS	1687.61	± 50%	Gamma (3.33, 0.002)
EEC	8135.03	± 50%	Gamma (2.33, 0.0003)
AEC	7701.55	± 50%	Gamma (0.03, 0.00004)
Annual treatment
SD/CIS	227.26	± 50%	Gamma (1.27, 0.006)
EEC	386.13	± 50%	Gamma (1.23, 0.003)
AEC	359.83	± 50%	Gamma (2.05, 0.006)
Characteristics of tests
Sensitivity of endoscopy	100%	0.88-1	-	Xia et al[18], 2021; Nagami et al[39], 2014; and Dawsey et al[40], 1998
Specificity of endoscopy	100%	0.59-1	-
Sensitivity of sponge cytology test	94.5%	0.888-0.975	Triangular (0.888, 0.945, 0.975)	Gao et al[8], 2023
Specificity of sponge cytology test	91.9%	0.912-0.925	Triangular (0.912, 0.919, 0.925)
Complication rate of endoscopic test	0.00023	0-0.002	Triangular (0, 0.00023, 0.0013)	Silvis et al[41], 1976 and Wang et al[42], 2019
Health state5				Xia et al[18], 2021 and Liu et al[20], 2018
mD	1	0.98-1	Triangular (0.98, 1.00, 1.00)
MD	1	0.98-1	Triangular (0.98, 1.00, 1.00)
SD/CIS	0.84	0.79-0.89	Beta (3.57, 0.68)
EEC	0.70	0.66-0.74	Beta (2.63, 1.13)
AEC	0.61	0.56-0.66	Beta (1.12, 0.71)
PT-SD/CIS	0.90	0.88-0.92	Beta (2.26, 0.25)
PT-EEC	0.81	0.79-0.83	Beta (1.77, 0.41)
PT-AEC	0.74	0.71-0.77	Beta (0.95, 0.33)
Discount rate	0.05	0-0.08		Liu et al[21], 2022

¹Upper and lower limits of parameters were determined based on a 95% confidence interval, a 50% range, or a range of estimates[22,43].

²Utilities were assigned a beta distribution, and costs were assigned a gamma distribution. A triangular distribution encompassed the range between the minimum.

³Baseline proportion of individuals in each disease state at model entry.

⁴Annual probabilities of moving between health states.

⁵Utilities scores: Quality-of-life weights for quality-adjusted life year. calculation; 0 = death, 1 = perfect health.

mD: Mild dysplasia; MD: Moderate dysplasia; SD/CIS: Severe dysplasia/carcinoma in situ; EEC: Early esophageal cancer; AEC: Advanced esophageal cancer; PT: Post-treatment.