Table 2.

Risk factors associated with poor bowel preparation on univariate and multivariate analyses

Patient characteristics	Quality of bowel preparation, n (%)		Unadjusted OR	95% CI	p value	Adjusted OR	95% CI	p value
	Poor n = 151	Non-poor n = 350
Age
< 65 years	80 (25.7)	231 (74.3)	1.00
≥ 65 years	71 (37.4)	119 (62.6)	1.74	1.19, 2.56	0.005	1.36	0.87, 2.10	0.17
Gender
Female	69 (21.2)	176 (71.8)	1.00			-	-	-
Male	82 (32.0)	174 (68.0)	1.20	0.82, 1.76	0.346
Education level
≥ Secondary	62 (20.5)	241 (79.5)	1.00			1.00
≤Primary	89 (44.4)	109 (55.6)	3.10	2.09, 4.61	< 0.001	2.35	1.54,3.60	< 0.001
Status
Out-patient	90 (25.4)	264 (74.6)	1.00			1.00
In-patient	61 (41.5)	86 (58.5)	2.08	1.39, 3.12	< 0.001	1.09	0.66, 1.81	0.73
Timing of colonoscopy
Morning	132 (31.4)	289 (68.6)	1.00			1.00
Evening	19 (23.7)	61 (76.7)	0.68	0.39, 1.19	0.176	0.70	0.37, 1.32	0.70
Appointment waiting time (weeks)
< 1	23 (21.3)	85 (78.7)	1.00			1.00
2 - 15	47 (31.8)	101 (68.2)	1.72	0.97, 3.06	0.065	1.52	0.81, 2.87	0.19
> 16	81 (33.1)	164 (66.9)	1.83	1.07, 3.11	0.027	1.86	1.04, 3.37	0.035
BMI
≥ 23	82 (30.8)	184 (69.2)	1.00			-	-	-
< 23	68 (29,4)	163 (70.6)	0.94	0.64, 1.38	0.736
Medical illness
No	73 (27.2)	195 (72.8)	1.00			1.00
Yes	75 (32.6)	155 (67.4)	1.29	0.88, 1.90	0.192	1.05	0.67, 1.62	0.84
Previous surgery
No	101 (28.0)	260 (72.0)	1.00			1.00
Yes	49 (35.5)	89 (64.5)	1.42	0.93, 2.15	0.101	1.17	0.73, 1.89	0.51
Previous colonoscopy
No	102 (30.2)	236 (69.8)	1.00			-	-	-
Yes	48 (29.8)	113 (70.2)	0.98	0.65, 1.48	0.934
Compliant to bowel preparation
Yes	80 (20.9)	303 (79.1)	1.00			1.00
No	71 (60.2)	47 (39.8)	5.72	3.67, 8.91	< 0.0001	4.76	3.0, 7.55	< 0.001