Table 1.
Overview of randomised controlled trials on impact of flexible sigmoidoscopy: design aspects
| Study | Country | No randomised (approached) | Age | Intervention | Years enrolled | Median follow-up (years) | No (%) with lower gastroinestinal endoscopy | Report of per protocol analysis | ||
|---|---|---|---|---|---|---|---|---|---|---|
| Intervention | Control | Adjusted for non-compliance | Adjusted for contamination | |||||||
| Hoff et al 200912 | Norway | 55 736 | 55-64 | Once only FS, with or without single FOBT | 1999-2000 | 7 | 8846/13 653 (64.8) | NR | Yes | No |
| Atkin et al 201013 | United Kingdom | 170 432 (368 142) | 55-64 | Once only FS | 1994-99 | 11.2 | 40 674/57 237 (71.1) | NR | Yes* | No |
| Segnan et al 201114 | Italy | 56 532 (236 536) | 55-64 | Once only FS | 1995-99 | 10.5 | 9999/17 148 (58.3) | NR | Yes* | No |
| Schoen et al 201215 | United States | 154 900 (NR) | 55-74 | FS at baseline and after 3-5 years | 1993-2001 | 11.9 | 67 071/77 445 (86.6) | NR (46.5) | No | No |
FOBT=faecal occult blood test; FS=flexible sigmoidoscopy; NR=not reported.
*With correction for potential differences in outcomes among non-responders and controls.