Table 1

Base-case estimates and ranges used in sensitivity analysis

Variable

Base-Case Values (Range)

Reference


The disease natural history and prognosis


Prevalence of colorectal neoplasm at age 50 years

Small adenoma

9.28% (4.64%–18.56%)

2–4, 17, 21*

Large adenoma

3.82% (0.96%–7.64%)

2–4, 17, 21*

Preclinical early CRC

0.12% (0.06%–0.24%)

2–4, 17, 21*

Preclinical late CRC

0.08% (0.04%–0.16%)

2–4, 17, 21*


Annual transition rates

Normal to small adenoma (λ1(t))

at age 50 years

0.00836 (0.00418–0.01672)

2–4, 17, 21*

at age 55 years

0.00990 (0.00495–0.01980)

2–4, 17, 21*

at age 60 years

0.01156 (0.00578–0.02312)

2–4, 17, 21*

at age 65 years

0.01333 (0.00667–0.02666)

2–4, 17, 21*

at age 70 years

0.01521 (0.00761–0.03042)

2–4, 17, 21*

Small adenoma to large adenoma (λ2)

0.0346 (0.0173–0.0692)

2–4, 17, 21*

Large adenoma to preclinical early CRC (λ3)

0.0215 (0.0108–0.0430)

2–4, 17, 21*

Preclinical early CRC to preclinical late CRC (λ4)

0.3697 (0.2678–0.4715)

22

Preclinical early CRC to clinical early CRC (λ5)

0.2382 (0.2055–0.2709)

22

Preclinical late CRC to clinical late CRC (λ6)

0.4852 (0.3207–0.6498)

22

Early CRC to CRC death (λ7)

0.0302 (0.0151–0.0604)

2–4, 23

Late CRC to CRC death (λ8)

0.2099 (0.1050–0.4198)

2–4, 23


Screening and diagnostic test characteristics


Flexible sigmoidoscopy reach

50 (50–60)

25


Sensitivity, %

Stool DNA testing

Small adenoma

8 (5–75)

16

Large adenoma

15 (12–82)

10–12, 16

Preclinical CRC

52 (50–100)

10–12, 16


FOBT

Small adenoma

5 (2–10)

26–31

Large adenoma

10 (5–20)

26–31

Preclinical CRC

50 (13–90)

26–31


Flexible sigmoidoscopy and colonoscopy

Small adenoma

78.5 (73–84)

25

Large adenoma

85 (85–90)

25

Preclinical CRC

95 (90–100)

25, 32–38


Specificity, %


Stool DNA testing

94 (89–100)

10–12, 16

FOBT

97.5 (95–100)

2–4

Flexible sigmoidoscopy

94 (92–96)

25

Colonoscopy

98 (96–100)

25


Complication of colonoscopy


Perforation rate, %

0.2 (0.07–0.85)

39–40

Death rate due to perforation, per 100,000

10 (0–50)

39–40


Costs, $


Screening

Stool DNA testing

44.1 (22.1–88.2)

Expert opinion

FOBT

0.6 (0.3–1.2)

BNHI

Flexible sigmoidoscopy

35.3 (17.6–70.6)

BNHI

Colonoscopy

66.2 (33.1–161.8)

BNHI


Treatment and confirmation

Pathological examination

20.6 (10.3–41.2)

BNHI

Biopsy

13.2 (6.6–26.5)

BNHI

Colonoscopy

66.2 (33.1–161.8)

BNHI

Polypectomy

42.4 (21.2–84.7)

BNHI

Initial cost for early CRC

3117.6 (1558.8–6235.3)

BNHI

Initial cost for late CRC

7705.9 (3852.9–15411.8)

BNHI

Continuing cost for CRC

176.5 (88.2–352.9)

BNHI

Terminal Care for CRC

7647.1 (3823.5–15294.1)

BNHI

Complication cost for perforation

1617.6 (808.8–3235.3)

BNHI

Complication cost for death

2735.3 (1367.6–5470.6)

BNHI


Discount rate, %

3 (0–7)


Abbreviations: CRC, colorectal cancer; FOBT, fecal occult blood testing; BNHI, Bureau of National Health Insurance.

* The estimates were obtained and re-estimated by combining several data sources [2–4, 17, 21].

Wu et al. BMC Cancer 2006 6:136   doi:10.1186/1471-2407-6-136

Open Data