Table 2. Mann-Whitney U test result of risk factors.

Characteristics	Total (n = 1800)	Patients with ADEs (n = 234)	Patients without ADEs (n = 1566)	Z	P
Age (years)	69.84±8.14	67.95±7.55	70.12±8.16	-4.125	<0.001
Length of stay	10.19±8.94	15.19±12.28	9.44±8.07	-7.679	<0.001
Number of medical diagnoses	4.70±3.31	5.73±3.74	4.55±3.21	-5.237	<0.001
Number of admissions in the previous 1-year	1.34±3.17	2.33±3.07	1.20±3.16	-10.001	<0.001
Drugs per patient	7.19±5.71	10.00±6.26	6.77±5.51	-7.938	<0.001
Doses per patient	92.63±140.74	157.91±228.43	82.87±119.45	-5.521	<0.001