Table 3 Odds ratios and 95% CI for difficult procedures.

Females

2.312

1.528-3.498

<0.0001

ASA=1

1

ASA=2

0.539

0.344-0.844

0.0070

ASA=3,4

1.043

0.531-2.050

0.9023

Highly-experienced specialist

1

Less experienced

1.925

1.046-3.541

0.0352

More experienced non-specialist

1.028

0.620-1.705

0.9151

Adequate bowel preparation

1

Presence of residual matter

1.465

0.917-2.339

0.1099

Inadequate bowel preparation

3.208

1.511-6.808

0.0024

Duration of procedure ≥17.5

1.633

1.050-2.538

0.0294