Evidence to suggest adoption of water exchange deserves broader consideration: Its pain alleviating impact occurs in 90% of investigators

Table 2 Variations among investigators

	Real-time maximum insertion pain, mean (95%CI)			P value
	WE (n =371)	WI (n = 338)	AICD (n = 382)
All investigators	2.8	3.8	4.4	< 0.00051
	(2.6-3.0)	(3.5-4.1)	(4.1-4.7)	WE vs WI < 0.00052
				WE vs AICD < 0.00052
				WI vs AICD 0.0022
Investigator	WE	WI	AICD	Females (%)	BMI (± SD)	Previous abdominal surgery (%)	Abdominal compression (%)	Loop reduction (%)	Insertion time, min (±SD)
1	2.1	4.0	4.7	46.3	26.1 (4.9)	51.3	57.5	61.3	13 (6.5)
	(1.7-2.5)	(3.4-4.7)	(4.1-5.3)
2	2.9	3.3	4.1	32.9	27.0 (4.8)	46.8	67.1	63.3	11 (5.5)
	(2.4-3.3)	(2.8-3.9)	(3.5-4.7)
3	2.3	2.3	4	28.6	27.5 (4.4)	7.1	57.1	7.1	11 (4.4)
	(1.0-3.6)	(1.0-3.6)	(2.9-5.2)
4	2.4	1.9	2.8	28.6	25.6 (4.2)	10.7	71.4	21.4	15 (6.7)
	(1.7-3.2)	(0.6-3.3)	(2.0-3.5)
5	2.9	3.7	3.5	46.2	24.6 (3.3)	7.7	92.3	84.6	9 (2.8)
	(1.8-4.0)	(2.3-5.1)	(2.2-4.8)
6	2.4	2.6	3.5	60.9	28.4 (6.8)	13.0	73.9	52.2	10 (4.0)
	(1.6-3.3)	(1.5-3.7)	(2.5-4.5)
7	2.4	3.7	4.3	17.6	26.4 (2.5)	41.2	64.7	82.4	12 (7.2)
	(1.6-3.2)	(2.3-5.1)	(3.0-5.6)
8	2.8	2.4	2.4	50.0	25.6 (4.0)	35.7	92.9	92.9	15 (5.2)
	(2.0-3.6)	(1.7-3.0)	(1.4-3.3)
9	2.9	4.1	6.0	37.7	28.4 (5.2)	45.9	36.1	34.4	9 (3.1)
	(2.3-3.5)	(3.4-4.9)	(5.3-6.7)
10	5.3	7.1	7.0	50	27.2 (5.6)	35.7	21.4	10.7	8 (3.0)
	(4.4-6.2)	(6.3-8.0)	(6.2-7.9)
P values	< 0.00051	< 0.00051	< 0.00051	0.0741	0.0251	< 0.00051	< 0.00051	< 0.00051	< 0.00051

¹ANOVA;

²χ². n: Number of patients; WE: Water exchange for insertion, insufflation with air or CO₂ for withdrawal; WI: Water immersion for insertion, insufflation with air or CO₂ for withdrawal; AICD: Insufflation with air or CO₂ for insertion and withdrawal; SD: Standard deviation; BMI: Body mass index.