Impact of pharmacy validation in a computerized physician order entry context

BACKGROUND: Computerised physician order entry offers a potential means of reducing prescribing errors, and can also increase the feasibility of pharmacy validation as a secondary filter for eliminating errors. The impacts of these two benefits have never been evaluated in combination. OBJECTIVE: To describe (i) the pharmacists' interventions during validation of drug prescriptions on a computerized physician order entry system, (ii) the impact of these interventions on the prescribing process and (iii) the extent to which computerized physician order entry was responsible for the identified errors. METHOD: Prospective collection of all medication order lines during five days in a tertiary care university hospital using computerized physician order entry for drug prescription. All orders were reviewed by a pharmacist. We described the frequency of pharmacy alerts and their short-term impact on the correction of potential prescribing errors (modification of the prescription). An independent committee reviewed their type and link with the computerized physician order entry system. RESULTS: About 399 (11%) prescription order lines, corresponding to 222 (52%) patients, required a pharmacy alert during the study period. Among the 81 pharmacy alerts targeted to the prescriber, 21 [26% (IC95% = 17-37%)] resulted in a modification of the prescription. Among the 95 potential prescribing error, the independent review committee judged 16 (17%) as potentially life-threatening and attributed 47 (49%) to the use of computerized physician order entry system (unit error, no use of typical order prespecified, prescription inconsistency or other). CONCLUSION: Pharmacy validation produced only a moderate short-term impact on the reduction of potential prescribing errors. However, pharmacy validation may also provide ongoing benefits by identifying necessary improvements in the computerized physician order entry system. Those improvements would allow pharmacists to concentrate on the most relevant interventions.