Table 1

Description of the quality of evidence demonstrating effectiveness of screening in reducing colorectal incidence and/or death6

Screening testDescription
Flexible sigmoidoscopyFour randomised controlled trials (n=458 002) showed that flexible sigmoidoscopy reduced CRC incidence and death compared with no screening.
GFOBT*Five randomised controlled trials (n=689 259) demonstrated that gFOBT reduced CRC incidence and death compared with no screening. One of these studies is still ongoing, but interim findings have aided in determining gFOBT’s effectiveness. Additionally, one clinical trial (n=91 199) also demonstrated that gFOBT may reduce CRC incidence and death compared with no screening.
Faecal Immunochemical Test†‡One large, prospective observational study (n=5 417 699) showed an associative reduction in CRC mortality compared with no screening.
ColonoscopyTwo prospective observational studies (n=436 927) indicate that colonoscopy may help decrease the incidence and death from CRC.
  • Created by the authors.

  • *Hemoccult II (Beckman Coulter).

  • †OC-Sensor (Eiken Chemical).

  • ‡HMJACK (Kyowa Medex).

  • CRC, colorectal cancer; gFOBT, Guaiac Faecal Occult Blood Test.