Table 1.
Characteristics of included studies on screening flexible sigmoidoscopy and colorectal cancer incidence and mortality
| Ref. | Location | Study period (median follow-up time) | Age range (yr) | No. of patients per group | Study design | Total number of CRC cases | Incidence rate1(95%CI) | Number of deaths due to CRC | CRC Mortality rate1 | Study quality |
| Atkin et al[18], 2010 | United Kingdom | 11.2 yr | 55-64 | (C): 113195 | FS | (C): 1818 | (C): 149 (143 -156) | (C): 538 | (C): 52 (48-56) | 7 |
| (S): 57237 | Colonoscopy on detection of high risk polyps | (S): 706 | (S): 114 (106-123) | (S): 189 | (S): 36 (31-41) | |||||
| Hoff et al[20], 2009 | Norway | 7 yr | 55-64 | (C): 41913 | FS/FS + FIT | (C): 362 | (C): 134 | (C): 99 | 7 | |
| Colonoscopy on detection of high risk polyps | (262 advanced CRC) | |||||||||
| (S): 13823 | (S): 123 | (S): 132 | (S): 24 | |||||||
| (78 advanced CRC) | ||||||||||
| Schoen et al[17], 2012 | United States | 11.9 yr | 55-74 | (C): 77455 | FS | (C): 1287 | (C): 152 (144-160) | (C): 341 | (C): 39 (35-43) | 8 |
| Follow-up FS at 3-5 yr | (537 advanced CRC) | |||||||||
| (S): 77445 | Colonoscopy on detection of any polyp | (S): 1012 | (S): 119 (112-127) | (S): 252 | (S): 29 (25-32) | |||||
| (381 advanced CRC) | ||||||||||
| Segnan et al[19], 2011 | Italy | 10.5 yr | 55-64 | (C): 17144 | FS | (C): 306 | (C): 176 (158-197) | (C): 83 | (C): 44 (36-65) | 7 |
| Colonoscopy for high risk Polyps | (152 advanced CRC) | |||||||||
| (S): 17148 | (S): 251 | (S): 144 (127-163) | (S): 65 | (S): 35 (37 -55) | ||||||
| (112 advanced CRC) |
1
Rate per 100000 person years of follow-up. (C): Control group; (S): Screened group; CRC: Colorectal cancer; FS: Flexible sigmoidoscopy.