The impact of computerized physician order entry on medication error prevention.
BACKGROUND
Medication errors are common, and while most such errors have little potential for harm they cause substantial extra work in hospitals. A small proportion do have the potential to cause injury, and some cause preventable adverse drug events.


OBJECTIVE
To evaluate the impact of computerized physician order entry (POE) with decision support in reducing the number of medication errors.


METHODS
Prospective time series analysis, with four periods.


METHODS
All patients admitted to three medical units were studied for seven to ten-week periods in four different years. The baseline period was before implementation of POE, and the remaining three were after. Sophistication of POE increased with each successive period.


METHODS
Physician order entry with decision support features such as drug allergy and drug-drug interaction warnings.


METHODS
Medication errors, excluding missed dose errors.


RESULTS
During the study, the non-missed-dose medication error rate fell 81 percent, from 142 per 1,000 patient-days in the baseline period to 26.6 per 1,000 patient-days in the final period (P < 0.0001). Non-intercepted serious medication errors (those with the potential to cause injury) fell 86 percent from baseline to period 3, the final period (P = 0.0003). Large differences were seen for all main types of medication errors: dose errors, frequency errors, route errors, substitution errors, and allergies. For example, in the baseline period there were ten allergy errors, but only two in the following three periods combined (P < 0.0001).


CONCLUSIONS
Computerized POE substantially decreased the rate of non-missed-dose medication errors. A major reduction in errors was achieved with the initial version of the system, and further reductions were found with addition of decision support features.
Bates
D W
DW
Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA. dwbates@bics.bwh.harvard.edu
Teich
J M
JM
Lee
J
J
Seger
D
D
Kuperman
G J
GJ
Ma'Luf
N
N
Boyle
D
D
Leape
L
L
D016303:Clinical Pharmacy Information Systems; D020000:Decision Support Systems, Clinical; D004360:Drug Therapy, Computer-Assisted; D064420:Drug-Related Side Effects and Adverse Reactions; D006784:Hospitals, Teaching / Q000706:statistics & numerical data; D006801:Humans; D008404:Massachusetts; D016347:Medical Records Systems, Computerized; D008508:Medication Errors / Q000145:classification / Q000517:prevention & control* / Q000706:statistics & numerical data; D008510:Medication Systems, Hospital; D014584:User-Computer Interface