Results of analysis conducted on study outcomes
| Outcome | OR (SE) | 95% CI | P value | |
| Lower | Upper | |||
| Logistic regression | ||||
| Pain (none/mild versus moderate/severe) (PO) | 1.13 (0.20) | 0.81 | 1.59 | 0.47 |
| ADR (no, yes) (KSO) | 1.45 (0.25) | 1.03 | 2.04 | 0.03 |
| Pain (none/mild/moderate versus severe) | 1.77 (0.87) | 0.68 | 4.62 | 0.24 |
| Maximum extent of insertion (descending or greater, no further than sigmoid) | 1.12 (0.15) | 0.87 | 1.45 | 0.39 |
| Entonox use (no or yes) | 1.32 (0.28) | 0.87 | 2.00 | 0.19 |
| Need for re-enema (no or yes) | 1.32 (0.34) | 0.79 | 2.20 | 0.28 |
| Need for patient position changes (no or yes) | 1.15 (0.18) | 0.84 | 1.55 | 0.38 |
| Technique conversion (no or yes) | −0.26 (0.09) | 0.13 | 0.52 | <0.01 |
| Ordinal logistic regression | ||||
| Pain felt 24 hours (none, mild, moderate or severe) | 1.21 (0.17) | 0.93 | 1.59 | 0.15 |
| Pain expected (less painful, as expected or more) | 1.23 (0.17) | 0.94 | 1.61 | 0.13 |
| Embarrassment (none, mild, moderate or severe) | 1.02 (0.13) | 0.79 | 1.32 | 0.86 |
| Satisfaction (very dissatisfied, neither, satisfied or very satisfied | 0.87 (0.12) | 0.66 | 1.15 | 0.33 |
| Repeat procedure (No, not sure or yes) | 0.66 (0.26) | 0.30 | 1.44 | 0.29 |
| Recommend procedure (No, not sure or yes) | 1.19 (0.42) | 0.59 | 2.38 | 0.63 |
| Abdominal pain (none, mild, moderate or severe) | 1.33 (0.20) | 0.99 | 1.80 | 0.06 |
| Nausea (none, mild, moderate or severe) | 1.95 (0.78) | 0.89 | 4.27 | 0.10 |
| Faint feeling (none, mild, moderate or severe) | 0.97 (0.28) | 0.55 | 1.71 | 0.91 |
| Bloating (none, mild, moderate or severe) | 1.22 (0.17) | 0.92 | 1.61 | 0.17 |
| Bottom soreness (none, mild, moderate or severe) | 1.07 (0.22) | 0.72 | 1.59 | 0.75 |
| Soiling (none, mild, moderate or severe) | 1.28 (0.36) | 0.74 | 2.23 | 0.38 |
| Bleeding (none, mild, moderate or severe) | 1.50 (0.60) | 0.69 | 3.28 | 0.31 |
| Sleep disturbance (none, mild, moderate or severe) | 0.95 (0.25) | 0.57 | 1.58 | 0.84 |
| Quality of mucosal views (BBPS) (inadequate, poor, good or excellent) | −0.77 (0.09) | 0.61 | 0.97 | 0.02 |
| Mixed regression models | COEF (SE) | |||
| Patient procedural pain (VAS) | 1.59 (1.28) | −0.92 | 4.11 | 0.22 |
| Sigmoid insertion time | −0.54 (0.15) | −0.84 | −0.24 | <0.01 |
| Sigmoid withdrawal time | −0.16 (0.17) | −0.50 | 0.18 | 0.35 |
| Overall procedure time | −0.70 (0.24) | −1.17 | −0.23 | <0.01 |
| Length of scope inserted | −0.04 (0.79) | −1.58 | 1.50 | 0.96 |
| Zero-inflated Poisson model | ||||
| Mean adenomas per procedure | 0.10 (0.18) | −0.26 | 0.45 | 0.60 |
ADR, adenoma detection rate; BBPS, Boston Bowel Preparation Scale; COEF, coefficient; KSO, key secondary outcome; PO, primary outcome; VAS, visual analogue scale; WAS, water-assisted sigmoidoscopy.