Table 3.

Summary data from systematically peer-reviewed literature evaluating medication error frequency before (pre) and after (post) implementation of computerized provider order entry (CPOE)

Author (year of publication)	CPOE implementation and study setting (hospital department)	Duration (months)		Medication orders		Medication errors		Rate per 1000 orders		Percentage difference (unweighted)*
		Pre	Post	Pre	Post	Pre	Post	Pre	Post
Bates et al (1999)10	Select medical and intensive care units (inpatient)	1.7	5.6	10070	42516	255	340	25	8	−68
Bizovi et al (2002)12	Emergency department	2	2	2326	2169	54	11	23	5	−78
Cordero et al (2004)13	NICU	6	6	136	117	16	0	118	0	−100
Evans et al (1998)14	Intensive care unit	24	12	1813	942	787	134	434	142	−67
Igboechi et al (2003)15	Hospital wide (inpatient)	24	12	1868274	934137	5441	1247	3	1	−54
Kim et al (2006)16	Pediatric oncology unit	8	9.9	1259	1116	84	69	67	62	−7
Mahoney et al (2007)17	Hospital wide (inpatient)	12	12	1452346	1390789	4815	2227	3	2	−52
Taylor et al (2008)11	NICU	11	9	254	272	50	31	197	114	−42
Walsh et al (2008)18	NICU, PICU, select pediatric medical and surgical units (inpatient)	7	9	5777	6895	106	155	18	22	23

*Our calculated summary statistic (presented in table 4) used the DerSimonian–Laird method (DL) to pool these data, where each study's DL weight was multiplied by the unweighted percentage difference shown. The DL effect sizes are not included here, as they are not scaled in a meaningful way.

NICU, neonatal intensive care unit; PICU, pediatric intensive care unit.