Table 2.

Randomized controlled studies comparing the water method and air insufflation for colonoscopy: number of enrolled patients, options for sedation, cecal intubation rate and outcomes (pain, willingness to repeat the procedure, recovery time)

Study	No. of patients		Sedation	Cecal intubation (%)		Outcame measures
						Pain score (0-10)		Willingness to repeat		Recovery time (min)
Colonoscopy studies	WW	Air		WW	Air	WW	Air	WW	Air	WW	Air
Leung JW et al[45] 2009	28	28	Minimal with increments as needed	100	100	1.3	4.1 0.0002	96%	96% NS	13.6	19.8
											0.0005
Radaelli et al[48] 2010	116	114	On-demand	94	95	2.8	3.9 0.05	90.50%	81.60% 0.05	NR	NR
Leung FW et al[46] 2010	42	40	unsedated	78	98	3.0	6 0.004	93%	78% 0.018	NR	NR
Leung CW et al[47] 2010	112	114	Minimal sedation	100	100	4.1	5.3 0.001	1.41	1.471 NS	NR	NR
Ransibrahmanakul K et al[49] 2010	31	31	Minimal sedation	94	94	3.6	5.5 0.05	93.50%	80.6 NS	8.8	10.4 NS
Leung JW et al[22] 2011	50	50	On-demand	100	100	2.3	4.9 0.001	90%	94% NS	8.4	12.3 0.019
Hseih YH et al[51] 2011	90	89	Minimal sedation	99.9	99.9	2.5	3.4 0.02	NR	NR	NR	NR
Pohl J et al[50] 2011	58	58	On-demand	82.8	96.5	2.8	4.2 0.02	72.40%	67.2% NS	NR	NR
Amato A et al[36] 2011	113	113	On-demand	97.3	99.1	2.8	4.6 0.01	90%	79.6% 0.03	0-8	0-53 NS

NR = Not reported;

¹Continuous Likert scale (1 = minimal; 7 = maximal); NS: Not significant.