Table 6.

 Odds ratios* (OR) for occurrence of at least one error in parenteral drug administration in intensive care unit (ICU). Univariate logistic regression

Variable	Variable measurement†	OR (95% CI)	P value
All observed types of parenteral drug administration errors
ICU size (beds)	1	1.02 (1.01 to 1.03)	<0.01
ICU type: medical	1	0.64 (0.42 to 0.96)	0.03
ICU type: mixed	1	1.57 (1.04 to 2.38)	0.03
Patients per nurse	1	1.26 (1.04 to 1.54)	0.02
CIRS in place	Yes/no	0.67 (0.53 to 0.84)	<0.01
Infusions previously prepared by pharmacist	Yes/no	1.32 (1.02 to 1.70)	0.03
No of different types of infusion pumps	1	0.89 (0.81 to 0.99)	0.03
Routine check at shift change	Yes/no	0.63 (0.50 to 0.81)	<0.01
Labelling of syringes	Yes/no	0.61 (0.44 to 0.86)	<0.01
Occupancy rate (%)	10	1.02 (1.00 to 1.05)	0.04
Relative turnover	1	0.75 (0.60 to 0.93)	0.01
Errors of commission (wrong dose, wrong drug, wrong route)
Hospital size (beds)	100	1.05 (1.02 to 1.08)	<0.01
ICU size (beds)	1	1.02 (1.01 to 1.03)	<0.01
Patients per nurse	1	1.51 (1.10 to 2.07)	0.01
Patients per physician	1	1.10 (1.01 to 1.20)	0.03
ICU beds per nurse	1	1.35 (1.02 to 1.77)	0.03
CIRS† in place	Yes/no	0.36 (0.24 to 0.54)	<0.01
Infusions previously prepared by pharmacist	Yes/no	2.32 (1.57 to 3.41)	<0.01
Electronic prescribing system in use	Yes/no	0.62 (0.40 to 0.95)	0.03
Errors requiring an intervention
CIRS in place	Yes/no	0.44 (0.26 to 0.75)	<0.01
Electronic prescribing system in use	Yes/no	0.43 (0.23 to 0.82)	0.01
No of different types of perfusors	1	1.16 (1.04 to 1.29)	0.01
Labelling of syringes	Yes/no	0.31 (0.18 to 0.56)	<0.01

CIRS=critical incident reporting system.

*Odds ratios calculated by using dependent variable “occurrence of at least one medication error” with patients as unit of analysis. Table displays unit related variables reaching significance in different sets of error.

†Increment or binary.