Table 1.

Duplicate ordering errors characteristics

	Pre-CPOE	Post-CPOE	p Value
Total duplicate errors	48	167	<0.0001
Duplicate errors per 1000 medication orders	1.05	5.09	<0.0001
Duplicate errors per 100 patient-days	1.16	4.16	<0.0001
Duplicate error subtypes
Identical order	15 (31%)	69 (41%)	<0.0001
Same medication	13 (27%)	75 (45%)
Same therapeutic class	20 (42%)	23 (14%)
Most frequently duplicated medication classes by rank order (number)
1	Gastrointestinal (9)	Electrolytes (30)
2	Electrolytes (8)	Gastrointestinal (23)
3	Narcotics, analgesics (6)	Cardiac (21)
4	Antibiotics (6)	Crystalloids, colloids, parenteral nutrition (20)
5	Crystalloids, colloids, parenteral nutrition (3)	Diuretics (13)
6	Steroids (3)	Antibiotics (12)
7	Insulin, antidiabetics (3)	Anticoagulants (11)
8	Cardiac (3)	Narcotics, analgesics (8)
Most frequently duplicated medications by rank order (number)
1	Potassium chloride and potassium phosphate (7)	Potassium chloride and potassium phosphate (23)
2	Acetaminophen, famotidine, insulin, pantoprazole (3 each)	Furosemide (13)
Time of day second duplicate order entered
07:00–14:59 h	19	75	NS
15:00–22:59 h	12	42
23:00–06:59 h	17	50
Time between orders*
Less than 10 min	6	41	NS
11–60 min	3	31
61–120 min	0	12
121–180 min	0	6
>180 min	8	20
Different days	4	31
Unknown but same day	20	12
Unknown	7	14

^*Events excluded from statistical testing if the exact time between orders is unknown (last two categories).

CPOE, computerized provider order entry.