Table 2

Adverse event (AE) risk and rate

	Overall	Cardiac surgery	Intensive care	Internal medicine	Obstetrics	p value (χ² test)
Risk^* N (%)
Patients observed	1406	226	211	453	516
Patients with at least one AE	192 (13.7%)	45 (19.9%)	52 (24.6%)	75 (16.6%)	20 (3.9%)	<0.001
Patients with at least one preventable AE	86 (6.1%)	8 (3.5%)	23 (10.9%)	48 (10.6%)	7 (1.4%)	<0.001
Patients with at least one potential AE	75 (5.3%)	6 (2.7%)	17 (8.1%)	40 (8.8%)	12 (2.3%)	<0.001
Rate^†
Days of observation	9300	1234	1592	5026	1448
AE rate (per 100 patient days)	245 (2.6)	62 (5.0)	72 (4.5)	89 (1.8)	22 (1.5)	<0.001
Preventable AE rate (per 100 patient days)	88 (0.9)	8 (0.6)	23 (1.4)	50 (1.0)	7 (0.5)	0.03
Potential AE rate (per 100 patient days)	81 (0.9)	7 (0.6)	20 (1.3)	42 (0.8)	12 (0.8)	0.24

↵* Risk was calculated as the number of patients with at least one event divided by the total number of patients observed.
↵† Rate reported as events per 100 patient days, which was calculated as the number of events divided by the number of patient days of observation multiplied by 100.