TABLE 5.

Average colonoscope withdrawal times

Study	Study design	Clinician specialty*	Patients/procedures, n	Average withdrawal time (min)
Nelson et al (18); Setting: 13 VA Medical Centers	Prospective	Gastroenterologists	3196 screening colonoscopies	20.1†
Denis et al (30); Setting: Single hospital	Prospective	Gastroenterologists (n=5)	500 colonoscopies	<6
Froelich et al (32); Setting: Multicentre (21 centres in 11 countries)	Prospective	Not reported	4535 patients	10.1
Barclay et al (33); Setting: Single institution	Prospective	Gastroenterologists (n=12)	2053 patients	6.3 with no polyps; 10.3 with polyps
Simmons et al (34); Setting: Single institution	Retrospective	Endoscopists (various, unspecified) (n=43)	10,955 colonoscopies	6.3

^*Unless shown, the number of persons performing the procedure was not reported in the paper;

^†Including polypectomy time. VA Veterans affairs