Table 4.

Factors Associated with Adverse Drug Events and Medication Errors

Factors	No. of patients	Adverse drug events			Medication errors
		n (%)	Crude OR (95% CI)	Adjusted OR (95% CI)*	n (%)	Crude OR (95% CI)	Adjusted OR (95% CI)*
Age (y)
<65	1304	203 (16)	–	–	149 (11)	–	–
≥65	2155	523 (24)	1.7 (1.5-2.1)	1.7 (1.5-2.1)	284 (13)	1.2 (0.95-1.5)	1.2 (0.9-1.5)
Gender
Female	1501	318 (21)	–	–	202 (13)	–	–
Male	1958	408 (21)	1.0 (0.8-1.2)	1.1 (0.9-1.3)	231 (12)	0.9 (0.7-1.05)	1.0 (0.8-1.3)
Admitted ward
Medicine	1531	350 (23)	–	–	182 (12)	–	–
Surgery	1469	306 (21)	0.9 (0.7-1.06)	1.0 (0.8-1.2)	201 (14)	1.2 (0.9-1.5)	1.7 (1.4-2.2)
ICU	459	70 (15)	0.6 (0.5-0.8)	0.6 (0.5-0.9)	50 (11)	0.9 (0.7-1.3)	1.2 (0.9-1.7)
Doctor in charge
Not resident physician	2526	499 (20)	–	–	205 (8)	–	–
Resident physician	933	227 (24)	1.3 (1.1-1.6)	1.2 (1.01-1.5)	228 (24)	3.7 (3.0-4.5)	3.9 (3.1-4.9)
Admission pathway
Scheduled	1609	320 (20)	–	–	215 (13)	–	–
Emergency admission	1810	391 (22)	1.1 (0.9-1.3)	1.2 (0.97-1.4)	201 (11)	0.8 (0.7-0.99)	0.8 (0.6-0.9)
Transferred from other ward	40	15 (38)	2.4 (1.3-4.6)	1.8 (0.9-3.6)	17 (43)	4.8 (2.5-9.1)	2.7 (1.2-4.8)
History of allergy
Absent	3117	640 (21)	–	–	368 (12)	–	–
Present	342	86 (25)	1.3 (1.003-1.7)	1.4 (1.04-1.8)	65 (19)	1.8 (1.3-2.3)	1.6 (1.1-2.1)
Medication on admission (No.)
<4	1532	316 (21)	–	–	138 (9)	–	–
≥4	1927	410 (21)	1.04 (0.9-1.2)	1.0 (0.9-1.2)	295 (15)	1.8 (1.5-2.3)	1.7 (1.4-2.2)

* Adjusted OR was calculated from multivariate logistic regression model with all listed variables.

ADE, adverse drug event; ICU, intensive care unit; OR, odds ratio; CI, confidence interval; -, reference