Table 7.

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

Variable	Variable measurement†	OR (95% CI)	P value
All observed types of parenteral drug administration errors
Patient related variables:
No of parenteral administrations	1	1.06 (1.04 to 1.08)	<0.01
No of organ failures	1	1.19 (1.05 to 1.34)	<0.01
NEMS item:
Basic monitoring	Yes/no	0.19 (0.07 to 0.49)	<0.01
IV medication	Yes/no	2.73 (1.39 to 5.36)	<0.01
Specific interventions in ICU	Yes/no	1.50 (1.14 to 1.96)	<0.01
ICU related variables:
ICU size (beds)	1	1.01 (1.00 to 1.02)	0.04
Patients per nurse	1	1.30 (1.03 to 1.64)	0.03
CIRS in place	Yes/no	0.69 (0.53 to 0.90)	<0.01
Routine check at shift change	Yes/no	0.68 (0.52 to 0.90)	<0.01
Occupancy rate (%)	10	1.03 (1.00 to 1.05)	0.03
Relative turnover	1	0.73 (0.57 to 0.93)	0.01
Errors of commission (wrong dose, wrong drug, wrong route)
Patient related variables:
No of parenteral administrations	1	1.05 (1.02 to 1.07)	<0.01
NEMS item:
Multiple vasoactive medication	Yes/no	2.43 (1.41 to 4.18)	<0.01
ICU related variables:
Patients per physician	1	1.12 (1.02 to 1.23)	0.01
CIRS in place	Yes/no	0.34 (0.22 to 0.52)	<0.01
Infusions previously prepared by pharmacist	Yes/no	2.36 (1.55 to 3.60)	<0.01
Errors requiring an intervention
Patient related variables:
No of parenteral administrations	1	1.08 (1.05 to 1.12)	<0.01
NEMS item:
Multiple vasoactive medication	Yes/no	2.63 (1.37 to 5.07)	<0.01
Specific interventions outside ICU	Yes/no	2.25 (1.16 to 4.39)	0.02
ICU related variables:
Electronic prescribing system in use	Yes/no	0.32 (0.16 to 0.64)	<0.01

NEMS=nine equivalents of nursing manpower use score; 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. Model accounts for patient and ICU characteristics and different sets of error.

†Increment or binary.