Research Paper: The Utility of Adding Retrospective Medication Profiling to Computerized Provider Order Entry in an Ambulatory Care Population

BACKGROUND We assessed whether medication safety improved when a medication profiling program was added to a computerized provider order entry system. DESIGN Between June 2001 and January 2002 we profiled outpatients with potential prescribing errors using computerized retrospective drug utilization software. We focused primarily on drug interactions. Patients were randomly assigned either to Provider Feedback or to Usual Care. Subsequent adverse drug event (ADE) incidence and other outcomes, including ADE preventability and severity, occurring up to 1 year following the last profiling date were evaluated retrospectively by a pharmacist blinded to patient assignment. MEASUREMENTS Data were abstracted using a study-designed instrument. An ADE was defined by an Adverse Drug Reaction Probability scale score of 1 or more. Statistical analyses included negative binomial regression for comparing ADE incidence. RESULTS Of 913 patients in the analytic sample, 371 patients (41%) had one or more ADEs. Incidence, by individual, was not significantly different between Usual Care and Provider Feedback groups (37% vs. 45%; p = 0.06; Coefficient, 0.19; 95% CI: -0.008, 0.390). ADE severity was also similar. For example, 51% of ADEs in the Usual Care and 58% in the Provider Feedback groups involved symptoms that were not serious (95% CI for the difference, -15%, 2%). Finally, ADE preventability did not differ. For example, 16% in the Usual Care group and 17% in the Provider Feedback group had an associated warning (95% CI for the difference, -7 to 5%; p = 0.79). CONCLUSION Medications safety did not improve with the addition of a medication profiling program to an electronic prescribing system.