Economic and medical benefits of ultrasound screenings for gallstone disease

Table 1 Cost assumptions, utility value, transition probabilities in decision analysis of screening for gallstone disease

Parameter	Value
Annual direct cost (NTD)
Screening cost1	1382
Regular clinics fee2	509
Laparoscopic cholecystectomy	11710
Hospitalizations and others	26825
Total	40426
Annual indirect cost (NTD)
Gross domestic product	635670
Utility (quality of life) value
No GSD	0.92 ± 0.10
Single stone	0.90 ± 0.12
Multiple stones	0.89 ± 0.19
Cholecystectomy	0.88 ± 0.08
Annual transition probability (%)[9]
No GSD → Single stone	5.05
Single stone → Multiple stones	10.00
Multiple stones → Cholecystectomy	13.76

¹Screening cost includes clinician’s fee, ultrasound examination, SMA-12 test, and manpower cost;

²Regular clinics fee includes clinician’s fee and pharmacist’s fee. GSD: Gallstone disease; NTD: New Taiwan dollars.

Table 2 Cost-effectiveness analysis and cost-utility analysis for different screening programs for gallstone disease during 10 years follow-up

Screening strategy	Cost (NTD)	Effectiveness(life-years gained)	Cost/effectiveness (NTD)	ICER (compared to control group)	Utility (QALY)	Cost/utility(NTD)	ICUR (compared to control group)
Annual	199856	5.1146	39076	Dominate1	4.9075	40725	Dominate1
Biennial	215231	3.7071	58059	Dominate1	3.3180	64868	Dominate1
3-yearly	253908	3.5183	72168	Dominate1	3.0037	84532	Dominate1
4-yearly	331477	3.1724	104488	Dominate1	2.9873	110962	Dominate1
5-yearly	368002	2.8990	126941	Dominate1	2.5906	142053	Dominate1
Control group	508117	2.5731	197473	-	2.5033	202979	-

¹Any screening program was more cost-effective than no program. ICER: Incremental cost-effectiveness ratio; ICUR: Incremental cost-utility ratio; NTD: New Taiwan dollars; QALY: Quality-adjusted life-year.

Table 3 Sensitivity analysis of cost-effectiveness analysis and cost-utility analysis of different screening programs for Gallstone disease

Variable	Base case	Range	Threshold of CEA	Threshold of CUA
Annual screening
Screening cost (NTD)	1382	1000-50000	41630	40082
Indirect cost (NTD)	231834	0-635670	Dominate1	Dominate1
Percentage of cholecystectomy	0.8	0.1-0.9	Dominate1	Dominate1
Biennial screening
Screening cost (NTD)	1382	1000-50000	38771	37250
Indirect cost (NTD)	231834	0-635670	Dominate1	Dominate1
Percentage of cholecystectomy	0.8	0.1-0.9	Dominate1	Dominate1
3-yr screening
Screening cost (NTD)	1382	1000-50000	36048	36003
Indirect cost (NTD)	231834	0-635670	Dominate1	Dominate1
Percentage of cholecystectomy	0.8	0.1-0.9	Dominate1	Dominate1
4-yr screening
Screening cost (NTD)	1382	1000-50000	32186	31952
Indirect cost (NTD)	231834	0-635670	Dominate1	Dominate1
Percentage of cholecystectomy	0.8	0.1-0.9	Dominate1	Dominate1
5-yr screening
Screening cost (NTD)	1382	1000-50000	29063	28579
Indirect cost (NTD)	231834	0-635670	Dominate1	Dominate1
Percentage of cholecystectomy	0.8	0.1-0.9	Dominate1	Dominate1

¹Any screening program was more cost-effective than no program. CEA: Cost-effectiveness analysis; CUA: Cost-utility analysis; NTD: New Taiwan dollars.