Table 1.

Summary of assumption.

	Parameter	Base case value	Reference
Sensitivity and specificity of screening and diagnosis	Sensitivity of FOBT for polyps/cancer	0.1/0.5	[15], [28], [29], [30]
	Sensitivity of colonoscopy for polyps/cancer	0.85/0.97	[2], [31], [32]
	Sensitivity of colon study for polyps/cancer	0.5/0.8	[2], [33], [34]
	Sensitivity of sigmoidoscopy for polyps/cancer	0.67	[1], [2], [31], [32]
	Specificity of FOBT	0.9	[15], [28], [29], [30]
	Specificity of colonoscopy	1	[2], [31], [32]
	Specificity of colon study	0.9	[2], [33], [34]
	Specificity of sigmoidoscopy	1	[2], [31], [32]
Natural history of polyp/cancer sequence	Prevalence of polyps at age 50	0.25	[13], [36]
	Annual polyp incidence rate	0.005	[13], [36]
	Percent of cancers originating as polyps	100%	[37], [38]
	Annual cancer incidence of polyp whose duration is below 5 yr	0.005	[17], [39], [40], [41]
	Annual cancer incidence of polyp whose duration is from 5 to 10 yr	0.01	[17], [39], [40], [41]
	Annual cancer incidence of polyp whose duration is above 10 yr	0.016	[17], [39], [40], [41]
	Dwelling time of cancer in early stages	2 yr	[29], [42]
	Percent of cancers detected in early stages with no screening	5%	[21]
	Five-year all cause survival for early cancer	90%	[21], [20]
	Five-year all cause survival for advanced cancer	54%	[20], [21], [23]
	Polyp recurrence rate after polypectomy in the first year	0.11	[2], [3]
	Polyp recurrence rate after polypectomy thereafter	0.03	[2], [3]
Complications and unintended consequences	Rate of perforation of colon in colonoscopy	0.002	[12], [13]
	Rate of perforation of colon in polypectomy	0.004	[12], [13]
	Rate of perforation from sigmoidoscopy	0.0001	[12], [13]
	Rate of perforation from colon study	0.00005	[7]
	Death rate from perforated colon	0.002	[16], [17]
Cost (won1)	Sigmoidoscopy	26620	[24]
	Colonoscopy	52560	[24]
	Colon study	58600	[24]
	FOBT	2290	[24]
	Polypectomy	134600	[24]
	Biopsy	24160	[24]
	Treatment of early cancer for first year	5150000	[3], [17], [23]
	Treatment of advanced cancer for first year	10300000	[3], [17], [23]
	Treatment of cancer after first year	2164000	[3], [17], [23]
	Treatment of colonic perforation	3000000	[3]

¹Exchange rate: 1200 Korean won for one US dollar.