Table 3. Logistic regression analysis of factors associated with inadequate bowel preparation using univariable and multivariable models.

Variable	Univariable model		Multivariable model
	OR (95 % CI)	P value	OR (95 % CI)	P value
Sex (female)	0.65 (0.39–1.09)	0.12	–	–
Age ( > 75 years) 1	1.46 (0.87–2.44)	0.19	–	–
Allocation group (intervention)	0.71 (0.43–1.19)	0.24	–	–
Stratum (bedridden)	2.51 (1.48–4.26)	0.001	1.55 (0.63–3.82)	0.35
PEG administration schema (same day)	4.14 (2.37–7.25)	< 0.001	4.97 (2.41–10.22)	< 0.001
Ingestion of less than 75 % of PEG solution (no)	6.73 (2.85–15.87)	< 0.001	2.23 (0.82–6.04)	0.12
Person informed about bowel preparation (patient)	0.66 (0.39–1.12)	0.15	–	–
ASA Score (> 2)	7.19 (3.82–13.55)	< 0.001	6.36 (2.67–15.14)	< 0.001
Katz Index (1≤ 3)	1.65 (0.96–2.83)	0.09	0.83 (0.30–2.33)	0.72
Diabetes mellitus (yes)	1.41 (0.75–2.62)	0.33	–	–
Chronic constipation (yes)	1.98 (0.93–4.21)	0.10	1.74 (0.68–4.45)	0.25
History of abdominal surgery (yes)	0.69 (0.33–1.47)	0.37	–	–
History of inadequate bowel preparation (yes)	0.72 (0.19–2.77)	0.75	–	–
Tricyclic antidepressants use (yes)	1.06 (0.38–2.96)	1	–	–
Opioids use (yes)	0.66 (0.60–0.72)	0.55	–	–

PEG, polyethylene glycol.

¹Cohort median.