This study investigated the cost-effectiveness between double and single Fecal Immunochemical Test(s) (FIT) in a mass CRC screening. A two-stage sequential screening was conducted. FIT was used as a primary screening test and recommended twice by an interval of one week at the first screening stage. We defined the first-time FIT as FIT1 and the second-time FIT as FIT2. If either FIT1 or FIT2 was positive (+), then a colonoscopy was recommended at the second stage. Costs were recorded and analyzed. A total of 24,419 participants completed either FIT1 or FIT2. The detection rate of advanced neoplasm was 19.2% among both FIT1+ and FIT2+, especially high among men with age ≥55 (27.4%). About 15.4% CRC, 18.9% advanced neoplasm, and 29.9% adenoma missed by FIT1 were detected by FIT2 alone. Average cost was $2,935 for double FITs and $2,121 for FIT1 to detect each CRC and $901 for double FITs and $680 for FIT1 to detect each advanced neoplasm. Double FITs are overall more cost-effective, having significantly higher positive and detection rates with an acceptable higher cost, than single FIT. Double FITs should be encouraged for the first screening in a mass CRC screening, especially in economically and medically underserved populations/areas/countries.
Colorectal cancer (CRC) is a significant burden on global health [
Among all FOBT methods, fecal immunochemical occult blood test (FIT) is recommended by the National Comprehensive Cancer Network, USA [
Permanent residents in Jiashan County, China, were our source population. Our inclusion criteria included all permanent residents who were living in the three randomly selected communities in Jiashan County and aged 40 to 74 years in Gan-Yao in 2007, Da-Yun in 2008, and Yao-Zhuang in 2009. Based on the inclusion criteria, 31,963 permanent residents from these three communities were our study population. All these eligible residents were invited to attend a free CRC screening program. A total of 24,419 study participants signed the written informed consent and participated in this CRC screening program. Basic characteristics of the study participants and positive predictive value of this screening have been reported by Cai et al. [
A two-stage sequential screening was designed and conducted. FIT was used as a primary screening test at the first stage of this mass CRC screening. Two stool samples were collected with an interval of one week by community health workers and tested in a local hospital by contracted experienced technicians. Three different parts were taken from each stool sample and then mixed and washed by special buffer solution. Each sample was collected in a bottle, about 5 mL moist stool content. All samples were tested in the laboratory immediately after collection. The second sample was collected in one week after the first one. FIT test using colloidal gold assay (monoclonal antibody) could detect a level of human hemoglobin as low as 0.05
All of the above examinations including FITs and colonoscopy were free to participants. Histopathological examination of CRC, adenoma, and nonadenomatous polyps has been reported by Cai et al. [
SPSS 16.0 software was used to do data analysis. Positive rate was calculated as the number of positive FITs divided by FIT participants. Detection rate was calculated as the number of detected cases divided by colonoscopy participants. Positive and detection rates in percent, odds ratios (ORs), and 95% confidence intervals (CIs) and the costs in both Renminbi, CNY (¥), and US dollars ($) were estimated by FIT and colonoscopy, respectively. Chi-squared tests were used to test the differences in positive and detection rates, and ORs between FIT1, FIT2, and FITs. If more than 20% expected frequencies of the events were below 5 in fourfold (two-by-two frequency) tables, then Fisher’s exact test was used and a rank test was used in multiple contingency tables. Advanced adenoma was defined as adenoma ≥10 mm, or with a histology showing either a ≥20% villous component or high grade dysplasia. Advanced neoplasm was defined as either CRC or advanced adenoma in the analyses.
The cost of FIT1 was CNY ¥8.00 (Renminbi) per case including ¥5.00 for the purchasement of test kits, ¥1.50 for sample collection, ¥0.50 for testing fee, and ¥1.00 for test organization. The cost of FIT2 was ¥7.00 per case because the fee for test organization has been done by FIT1. The total cost of colonoscopy was ¥270.00 per case. The currency exchange rate between CNY Yuan and US dollar was ¥6.357 for one USD ($1.00) on August 27, 2012. Other costs such as CRC treatment fees were paid by participants themselves.
The overall compliance rate for FITs was 76.4%, with 24,419 participants completing at least one FIT (either FIT1 or FIT2) among the total study population (
Odds ratio (OR) and 95% confidence interval (CI) of fecal immunochemical test (FIT) positive and compliance to colonoscopy by gender, age group, and FIT status in the Jiashan mass colorectal cancer screening program in China, 2007–2009.
Gender | Age | FIT | Participant | Positive | OR1 (95% CI) | OR2 (95% CI) | Colonoscopy | OR1 (95% CI) | OR2 (95% CI) |
---|---|---|---|---|---|---|---|---|---|
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Men | Age <55 | FIT1 | 6,435 | 219 (3.4) | 1.00 | 182 (83.1) | 1.00 | ||
FIT2 | 5,314 | 196 (3.7) | 1.09 (0.89–1.32) | 1.00 | 162 (82.7) | 0.97 (0.58–1.62) | 1.00 | ||
Both | 5,302 | 62 (1.2) | 0.34 (0.25–0.45) | 0.31 (0.23–0.41) | 54 (87.1) | 1.37 (0.60–3.12) | 1.42 (1.62–3.23) | ||
Either | 6,447 | 353 (5.5) | 1.64 (1.38–1.95) | 1.51 (1.27–1.81) | 294 (83.3) | 1.01 (0.65–1.59) | 1.05 (0.66–1.66) | ||
Age ≥55 | FIT1 | 5,352 | 327 (6.1) | 1.00 | 245 (74.9) | 1.00 | |||
FIT2 | 4,589 | 253 (5.5) | 0.90 (0.76–1.07) | 1.00 | 196 (77.5) | 1.15 (0.78–1.70) | 1.00 | ||
Both | 4,580 | 93 (2.0) | 0.32 (0.25–0.40) | 0.36 (0.28–0.45) | 73 (78.5) | 1.22 (0.70–2.13) | 1.06 (0.60–1.89) | ||
Either | 5,361 | 487 (9.1) | 1.54 (1.33–1.78) | 1.71 (1.46–2.00) | 368 (75.6) | 1.04 (0.75–1.43) | 0.90 (0.63–1.29) | ||
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Women | Age <55 | FIT1 | 6,921 | 297 (4.3) | 1.00 | 257 (86.5) | 1.00 | ||
FIT2 | 5,918 | 224 (3.8) | 0.88 (0.74–1.05) | 1.00 | 198 (88.4) | 1.54 (0.87–2.72) | 1.00 | ||
Both | 5,911 | 64 (1.1) | 0.24 (0.19–0.32) | 0.28 (0.21–0.37) | 57 (89.1) | 1.27 (0.54–2.97) | 1.07 (0.44–2.59) | ||
Either | 6,928 | 457 (6.6) | 1.58 (1.36–1.83) | 1.80 (1.52–2.12) | 398 (87.1) | 1.05 (0.68–1.62) | 0.89 (0.54–1.45) | ||
Age ≥55 | FIT1 | 5,667 | 304 (5.4) | 1.00 | 237 (78.0) | 1.00 | |||
FIT2 | 5,065 | 242 (4.8) | 0.89 (0.74–1.05) | 1.00 | 198 (81.8) | 1.27 (0.83–1.95) | 1.00 | ||
Both | 5,049 | 82 (1.6) | 0.29 (0.23–0.37) | 0.33 (0.26–0.42) | 66 (80.5) | 1.17 (0.63–2.15) | 0.92 (0.49–1.73) | ||
Either | 5,683 | 464 (8.0) | 1.57 (1.35–1.82) | 1.77 (1.51–2.08) | 369 (79.5) | 1.10 (0.77–1.56) | 0.86 (0.58–1.28) | ||
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Men | All | FIT1 | 11,787 | 547 (4.6) | 1.00 | 432 (79.0) | 1.00 | ||
FIT2 | 9,903 | 449 (4.5) | 0.98 (0.86–1.11) | 1.00 | 358 (79.7) | 1.05 (0.77–1.43) | 1.00 | ||
Both | 9,882 | 155 (1.6) | 0.33 (0.27–0.39) | 0.34 (0.28–0.40) | 127 (81.9) | 1.21 (0.76–1.91) | 1.15 (0.72–1.84) | ||
Either | 11,808 | 841 (7.1) | 1.58 (1.41–1.76) | 1.62 (1.44–1.82) | 663 (78.8) | 0.99 (0.76–1.29) | 0.95 (0.71–1.26) | ||
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Women | All | FIT1 | 12,588 | 600 (4.8) | 1.0 | 494 (82.2) | 1.0 | ||
FIT2 | 10,983 | 459 (4.2) | 0.87 (0.77–0.99) | 1.0 | 396 (85.0) | 1.23 (0.88–1.70) | 1.0 | ||
Both | 10,960 | 145 (1.3) | 0.27 (0.22–0.32) | 0.31 (0.26–0.37) | 123 (84.2) | 1.16 (0.71–1.89) | 0.95 (0.57–1.58) | ||
Either | 12,611 | 914 (7.2) | 1.56 (1.40–1.74) | 1.79 (1.60–2.01) | 767 (83.3) | 1.08 (0.82–1.42) | 0.88 (0.65–2.20) | ||
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Total | FIT1 | 24,375 | 1,148 (4.7) | 1.0 | 926 (80.7) | 1.0 | |||
FIT2 | 20,886 | 915 (4.4) | 0.93 (0.85–1.01) | 1.0 | 754 (82.4) | 1.12 (0.90–1.41) | 1.0 | ||
Both | 20,842 | 301 (1.4) | 0.30 (0.26–0.34) | 0.32 (0.28–0.37) | 250 (83.1) | 1.18 (0.84–1.64) | 1.05 (0.74–1.48) | ||
Either | 24,419 | 1,762 (7.2) | 1.57 (1.46–1.70) | 1.70 (1.56–1.84) | 1,430 (81.2) | 1.03 (0.86–1.25) | 0.92 (0.75–1.13) |
FIT1, the first FIT; FIT2, the second FIT; OR1 using FIT1 as reference; and OR2 using FIT2 as reference.
The positive rate was 4.7% (1,148/24,375) by FIT1 and 4.4% (915/20,886) by FIT2. There was no statistical difference in the positive rate between by FIT1 and FIT2 (
There were 39 CRCs and 211 adenomas (88 advanced adenomas and 123 nonadvanced adenomas) patients including 127 advanced neoplasms patients detected by colonoscopy among 1,430 participants with positive FITs. ORs and 95% CIs of detection of CRC and adenoma using colonoscopy as a gold standard by gender, age group, and FIT status are presented in Table
Odds ratio (OR) and 95% confidence interval (CI) of detection of colorectal cancer (CRC) and adenoma using colonoscopy as a gold standard by gender, age group, and fecal immunochemical test (FIT) status in the Jiashan mass CRC screening program in China, 2007–2009.
Gender/age | FIT | Colonoscopy participant | CRC | OR1 (95% CI) | OR2 (95% CI) | OR3 (95% CI) | Adenoma | OR1 (95% CI) | OR2 (95% CI) | OR3 (95% CI) |
---|---|---|---|---|---|---|---|---|---|---|
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Men |
FIT1 | 182 | 1 (100.0) | 1.00 | 1.0 | 37 ( |
1.00 | 1.0 | ||
FIT2 | 162 | 1 (100.0) | 1.12 (0.07–18.12) | 1.00 | 1.0 | 25 ( |
0.72 (0.41–1.25) | 1.00 | 1.0 | |
Both | 54 | 1 (100.0) | 3.42 (0.21–55.53) | 3.04 (0.19–49.42) | 1.0 | 13 ( |
1.24 (0.60–2.56) | 1.74 (0.82–3.70) | 1.0 | |
Either | 294 | 1 (100.0) | 0.62 (0.38–9.94) | 0.55 (0.03–8.84) | 1.0 | 49 ( |
0.78 (0.49–1.26) | 1.10 (0.65–1.85) | 1.0 | |
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Men |
FIT1 | 245 | 19 (86.4) | 1.00 | 15.23 (2.02–114.75) |
65 ( |
1.00 | 1.42 (0.89–2.24) | ||
FIT2 | 196 | 13 (59.1) | 0.85 (0.41–1.76) | 1.00 | 11.44 (1.48–88.40) |
48 ( |
0.90 (0.58–1.38) | 1.00 | 2.10 (1.23–3.58) | |
Both | 73 | 10 (45.5) | 1.89 (0.84–4.27) | 2.23 (0.93–5.35) | 8.41 (1.04–67.87) |
23 ( |
1.27 (0.72–2.25) | 1.42 (0.79–2.56) | 1.45 (0.66–3.22) | |
Either | 368 | 22 (100.0) | 0.76 (0.40–1.43) | 0.90 (0.44–1.82) | 18.63 (2.50–139.05) |
90 ( |
0.90 (0.62–1.30) | 1.00 (0.67–1.49) | 1.62 (1.10–2.39) | |
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Women |
FIT1 | 257 | 3 (75.0) | 1.00 | 1.0 | 16 ( |
1.00 | 1.0 | ||
FIT2 | 198 | 2 (50.0) | 0.86 (0.14–5.22) | 1.00 | 1.0 | 14 ( |
1.15 (0.55–2.41) | 1.00 | 1.0 | |
Both | 57 | 1 (25.0) | 1.51 (0.15–14.81) | 1.75 (0.16–19.66) | 1.0 | 5 ( |
1.45 (0.51–4.13) | 1.26 (0.44–3.67) | 1.0 | |
Either | 398 | 4 (100.0) | 0.86 (0.19–3.87) | 1.00 (0.18–5.48) | 1.0 | 25 ( |
1.01 (0.53–1.93) | 0.88 (0.45–1.74) | 1.0 | |
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Women |
FIT1 | 237 | 10 (83.3) | 1.00 | 3.73 (1.01–13.72) |
30 ( |
1.00 | 2.18 (1.16–4.12) | ||
FIT2 | 198 | 8 (66.7) | 0.96 (0.37–2.47) | 1.00 | 4.13 (0.87–19.68) |
30 ( |
1.23 (0.71–2.13) | 1.00 | 2.35 (1.20–4.58) | |
Both | 66 | 6 (50.0) | 2.27 (0.79–6.50) | 2.38 (0.79–7.12) | 5.60 (0.65–47.98) |
13 ( |
1.69 (0.83–3.47) | 1.37 (0.67–2.82) | 2.55 (0.85–7.66) | |
Either | 369 | 12 (100.0) | 0.76 (0.32–1.80) | 0.80 (0.32–1.99) | 3.31 (1.06–10.36) |
47 ( |
1.01 (0.62–1.64) | 0.82 (0.50–1.34) | 2.18 (1.31–3.62) | |
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Men |
FIT1 | 432 | 20 (87.0) | 1.0 | 1.0 | 102 ( |
1.0 | 1.0 | ||
FIT2 | 358 | 14 (60.1) | 0.84 (0.42–1.69) | 1.0 | 1.0 | 73 ( |
0.83 (0.59–1.16) | 1.0 | 1.0 | |
Both | 127 | 11 (47.8) | 1.95 (0.91–4.19) | 2.33 (1.03–5.28) | 1.0 | 36 ( |
1.28 (0.82–2.00) | 1.54 (0.97–2.46) | 1.0 | |
Either | 663 | 23 (100.0) | 0.74 (0.40–1.37) | 0.88 (0.45–1.74) | 1.0 | 139 ( |
0.86 (0.64–1.15) | 1.04 (0.75–1.42) | 1.0 | |
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Women |
FIT1 | 494 | 13 (81.3) | 1.0 | 0.56 (0.27–1.13) |
46 ( |
1.0 | 0.33 (0.23–0.48) | ||
FIT2 | 396 | 10 (62.5) | 0.96 (0.42–2.21) | 1.0 | 0.64 (0.28–1.45) |
44 ( |
1.22 (0.79–1.88) | 1.0 | 0.49 (0.33–0.73) | |
Both | 123 | 7 (43.8) | 2.23 (0.87–5.72) | 2.33 (0.87–6.26) | 0.64 (0.24–1.70) |
18 ( |
1.67 (0.93–3.00) | 1.37 (0.76–2.47) | 0.43 (0.23–0.82) | |
Either | 767 | 16 (100) | 0.79 (0.38–1.65) | 0.82 (0.37–1.83) | 0.59 (0.31–1.13) |
72 ( |
1.01 (0.68–1.49) | 0.83 (0.56–1.23) | 0.39 (0.29–0.53) | |
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Total | FIT1 | 926 | 33 (84.6) | 1.0 | — | 148 ( |
1.0 | — | ||
FIT2 | 754 | 24 (61.5) | 0.89 (0.52–1.52) | 1.0 | — | 117 ( |
0.97 (0.74–1.26) | 1.0 | — | |
Both | 250 | 18 (46.2) | 2.10 (1.16–3.80) | 2.36 (1.26–4.43) | — | 54 ( |
1.45 (1.02–2.05) | 1.50 (1.05–2.15) | — | |
Either | 1,430 | 39 (100.0) | 0.76 (0.47–1.22) | 0.85 (0.51–1.43) | — | 211 ( |
0.91 (0.72–1.14) | 0.94 (0.74–1.21) | — |
FIT1, the first FIT; FIT2, the second FIT; OR1 using FIT1 as reference and OR2 using FIT2 as reference; OR3
Table
Odds ratio (OR) and 95% confidence interval (CI) of detection of advanced neoplasm using colonoscopy as a gold standard by gender, age group, and fecal immunochemical test (FIT) status in the Jiashan mass colorectal cancer screening program in China, 2007–2009.
Gender | Age | FIT | Colonoscopy participant | Advanced neoplasm | OR1 (95% CI) | OR2 (95% CI) | OR3 (95% CI ) |
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Men | <55 | FIT1 | 182 | 23 (12.6) | 1.0 | 1.0 | |
FIT2 | 162 | 15 (9.3) | 0.71 (0.35–1.40) | 1.0 | 1.0 | ||
Both | 54 | 11 (20.4) | 1.77 (0.80–3.91) | 2.51 (1.07–5.86) | 1.0 | ||
Either | 294 | 27 (9.2) | 0.70 (0.39–1.26) | 0.99 (0.51–1.92) | 1.0 | ||
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Men | ≥55 | FIT1 | 245 | 42 (17.1) | 1.0 | 1.43 (0.83–2.48) | |
FIT2 | 196 | 28 (14.3) | 0.81 (0.48–1.36) | 1.0 | 1.63 (0.84–3.18) | ||
Both | 73 | 20 (27.4) | 1.82 (0.99–3.37) | 2.26 (1.18–4.34) | 1.48 (0.64–3.41) | ||
Either | 368 | 50 (13.6) | 0.76 (0.49–1.19) | 0.94 (0.57–1.55) | 1.56 (0.95–2.55) | ||
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Women | <55 | FIT1 | 257 | 11 (4.3) | 1.0 | 1.0 | |
FIT2 | 198 | 7 (3.5) | 0.82 (0.31–2.15) | 1.0 | 1.0 | ||
Both | 57 | 4 (7.0) | 1.69 (0.52–5.51) | 2.06 (0.59–7.30) | 1.0 | ||
Either | 398 | 14 (3.5) | 0.82 (0.36–1.83) | 1.0 (0.40–2.51) | 1.0 | ||
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Women | ≥55 | FIT1 | 237 | 27 (11.4) | 1.0 | 2.88 (1.39–5.94) | |
FIT2 | 198 | 22 (11.1) | 0.97 (0.54–1.77) | 1.0 | 3.41 (1.42–8.18) | ||
Both | 66 | 13 (19.7) | 1.91 (0.92–3.95) | 1.96 (0.93–4.16) | 3.25 (1.00–10.61) | ||
Either | 369 | 36 (9.8) | 0.84 (0.50–1.43) | 0.87 (0.49–1.52) | 2.97 (1.57–5.59) | ||
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Men | All | FIT1 | 432 | 65 (15.0) | 1.0 | 1.0 | |
FIT2 | 358 | 43 (12.0) | 0.77 (0.51–1.17) | 1.0 | 1.0 | ||
Both | 127 | 31 (24.4) | 1.82 (1.13–2.96) | 2.34 (1.41–3.96) | 1.0 | ||
Either | 663 | 77 (11.6) | 0.74 (0.52–1.06) | 0.96 (0.65–1.43) | 1.0 | ||
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Women | All | FIT1 | 494 | 38 (7.7) | 1.0 | 0.47 (0.31–0.72) | |
FIT2 | 396 | 29 (7.3) | 0.95 (0.57–1.57) | 1.0 | 0.58 (0.35–0.95) | ||
Both | 123 | 17 (11.4) | 1.93 (1.05–3.54) | 2.03 (1.07–3.84) | 0.50 (0.26–0.95) | ||
Either | 767 | 56 (7.3) | 0.95 (0.62–1.45) | 1.00 (0.63–1.59) | 0.60 (0.42–0.86) | ||
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Both | All | FIT1 | 926 | 103 (11.1) | 1.0 | — | |
FIT2 | 754 | 72 (9.5) | 0.84 (0.61–1.16) | 1.0 | — | ||
Both | 250 | 48 (19.2) | 1.90 (1.30–2.76) | 2.25 (1.51–3.35) | — | ||
Either | 1,430 | 127 (8.9) | 0.78 (0.59–1.02) | 0.92 (0.68–1.25) | — |
FIT1, the first FIT; FIT2, the second FIT; OR1 using FIT1 as reference and OR2 using FIT2 as reference; OR3
The detection rates of various colorectal neoplasm by different positive combinations of double FITs are presented in Table
Odds ratio (OR) and 95% confidence interval (CI) of detection of various colorectal neoplasm using colonoscopy as a gold standard by different positive combinations of double fecal immunochemical tests (FITs) in the Jiashan mass colorectal cancer (CRC) screening program in China, 2007–2009.
FIT1 | FIT2 | FITs | Positive | Colonoscopy | Results: | |||
---|---|---|---|---|---|---|---|---|
|
|
|
CRC | Advanced adenoma | Nonadvanced adenoma | Advanced neoplasm | ||
+ | − | 20,842 | 763 | 619 | 12, 1.9, 30.1 | 37, 6.0, 42.0 | 49, 7.9, 39.8 | 49, 7.9, 38.6 |
+ | + | 20,842 | 301 | 250 | 18, 7.2, 46.2 | 30, 12.0, 34.1 | 24, 9.6, 19.5 | 48, 19.2, 37.8 |
+ | Absent | 3,533 | 84 | 57 | 3, 5.3, 7.7 | 3, 5.3, 3.4 | 5, 8.8, 4.1 | 6, 7.1, 4.7 |
− | + | 20,842 | 609 | 500 | 6, 1.2, 15.4 | 18, 3.6, 20.5 | 44, 8.8, 35.8 | 24, 4.8, 18.9 |
Absent | + | 44 | 5 | 4 | 0 | 0 | 1, 25.0, 0.5 | 0 |
FIT1+ |
24375 | 1,148 | 926 | 33, 3.6, 84.6 | 70, 7.6, 79.5 | 78, 8.4, 63.4 | 103, 11.1, 81.1 | |
FIT2+ |
20886 | 915 | 754 | 24, 3.2, 61.5 | 48, 6.4, 54.5 | 69, 9.2, 56.1 | 72, 9.5, 56.7 | |
Total | 24,419 | 1,762 | 1,430 | 39, 2.7, 100.0 | 88, 6.2, 100.0 | 123, 8.6, 100.0 | 127, 8.9, 100.0 | |
OR (95% CI) of detection rate by FIT (FIT2 versus FIT1) | 0.85 (0.50–1.44) | 0.80 (0.55–1.16) | 1.03 (0.75–1.43) | 0.82 (0.60–1.10) | ||||
OR (95% CI ) of detection rate by FIT (FITs versus FIT1) | 1.18 (0.74–1.88) | 1.26 (0.92–1.72) | 1.58 (1.19–2.10) | 1.38 (1.07–1.80) |
FIT1, the first FIT; FIT2, the second FIT; FITs, combination of FIT1 and FIT2.
Costs in both Chinese Renminbi, CNY (¥), and US dollar ($) and detected CRC and advanced neoplasm by comparing double FITs to single FIT are presented in Table
Costs in both Chinese Renminbi, CNY (
FIT | Colonoscopy | CRC | Advanced neoplasm | ||||||
---|---|---|---|---|---|---|---|---|---|
Participant | Total cost ( |
Positive | Participant | Total cost ( |
Number | Cost ( |
Number | Cost ( |
|
FIT1 | 24,375 | 195,000/30,675 | 1,148 | 926 | 250,020/39,330 | 33 | 13,485/2,121 | 103 | 4,321/680 |
FIT2 | 20,886 | 146,202/22,999 | 915 | 754 | 203,580/32,025 | 24 | 14,574/2,293 | 72 | 4,858/764 |
Both | 20,842 | 312,630/49,179 | 301 | 250 | 67,500/10,618 | 18 | 21,118/3,322 | 48 | 7,919/1,246 |
Either | 24,419 | 341,510/53,722 | 1,762 | 1,430 | 386,100/60,736 | 39 | 18,657/2,935 | 127 | 5,729/901 |
FIT2 only | 20,886 | 146,202/22,999 | 614 | 504 | 136,080/21,406 | 6 | 47,047/7,401 | 24 | 11,762/1,850 |
FIT1, the first FIT; FIT2, the second FIT; FIT2 only refers to those who completed FIT2 without the completion of FIT1.
This study investigated the performance of double FITs comparing to single FIT in a mass CRC screening in a rural population in China. The major findings indicated that double FITs were overall more cost-effective than single FIT. The positive rate was improved by double FITs comparing to FTI1 or FIT2 alone. The compliance rate for colonoscopy between FIT1 and FIT2 was similar. The detection rate of advanced neoplasm by double FITs was significantly improved comparing to FIT1. Double FITs found 18% more CRC and 38% more colorectal advanced neoplasms than single FIT1. A total of 15.4% (6/39) CRC, 18.9% advanced neoplasm, and 29.9% adenoma (including 20.5% advanced adenoma and 35.8% nonadvanced adenoma) detected by FIT2 alone would have been missed if only FIT1 had been used in the primary screening. The cost for CRC and advanced neoplasm detected by double FITs was increased about 33–38% which is acceptable and inexpensive comparing to 30 (6 CRC and 24 advanced neoplasm cases) lives saved from dying of colorectal advanced neoplasm cases and hundreds of other colorectal lesions cases prevented from developing CRC detected by FIT2 alone.
Some people in the community feel inconvenient and uncomfortable to collect stool samples, but stool samples are easily accessible and transportable, involving no painful procedure for collection, and can be done in privacy at home. Studies show that serum biomarkers such as M2PK and carcinoembryonic antigen (CEA) and/or combinations of these biomarkers could be a promising primary screening test in mass CRC screening [
Overall, FOBT is relatively easy, safe, inexpensive, and acceptable comparing to colonoscopy which is limited by high cost, low participation rate, and variation in performance according to the endoscopist and high risk of pain and other adverse side effects [
Sobhani has reported that screening program using FITs with three samples collected from three different parts of one-time stool at the same time is cost-effective [
The detection rate of advanced neoplasm and nonadvanced adenoma was significantly improved by 38–58% in double FITs+ compared to that in FIT1+. The detection rates of CRC and advanced adenoma were not significantly improved maybe due to a small number of CRC and advanced adenoma cases being detected. If the mass screening is applied among a larger population, the detection rates of both CRC and advanced adenoma would be significantly improved.
In our study, a total of 61.5% (24/39) CRC cases were detected at an early stage (
This study has some strengths. This is a large mass screening in a rural population in China. The compliance rate is relatively high. Our study design of two FITs by an interval of one week at the first screening stage can (1) help detect some colorectal lesions with intermittent bleeding which one FIT and two or more FITs from one sample may miss and the second FIT in one or two year(s) may be too late to diagnose, (2) save additional costs such as screening organization fees, and (3) increase compliance to the second FIT in one week. The cost analysis is based on the actual spent dollars and a comparative analysis between double FITs and single FIT within this screening program. The future benefits from this screening have not been included. Overall, results from this screening are reliable and valid. There are some limitations in this study. Some nonbleeding colorectal lesions may be missed due to the default of FOBT. False negative and false positive rates are relatively high because FITs have a relatively low sensitivity and specificity FIT comparing to colonoscopy.
Double FITs are more cost-effective than single FIT in our mass CRC screening based on the evidence of having significantly higher positive and detection rates with an acceptable higher cost by double FITs than single FIT. Double FITs should be encouraged for the first screening in a mass CRC screening, especially in economically and medically underserved populations/areas/countries.
The authors declare that they have no competing interests.
Shan-Rong Cai and Hong-Hong Zhu equally contributed to the work.
This study was supported by the China National 11th Five-Year Scientific Project (Grant no. 2006BA2A08) and a Special Fund to the Local Public Health by the China National Fiscal Supplement—National Cancer Early Detection and Treatment Program (2006–2009, Ministry of Health, Ministry of Finance, China), and Zhejiang Medical and health science and technology project (2013KYA091). The authors thank the members of the China National Committee of Cancer Early Detection and Treatment and all general practitioners in the study communities, and doctors and nurses of the local hospitals in the study population including Gan-Yao, Da-Yun, and Yao-Zhuang communities in Jia-Shan County. Also, the authors are thankful for the support from the Board of Health in Jia-Shan County and community workers involved in this study.