The ai
m of this study was to deter
mine characteristics of drug allergy alert overrides, assess how often they lead to preventable adverse drug events (ADEs), and suggest
methods for i
mproving the allergy-alerting syste
m.
Design
Chart review was performed on a stratified random subset of all allergy alerts occurring during a 3-month period (August through October 2002) at a large academic hospital.
Measurements
Factors that were measured were drug/allergy combinations that triggered alerts, frequency of specific override reasons, characteristics of ADEs, and completeness of allergy documentation.
Results
A total of 6,182 (80 % ) of 7,761 alerts were overridden in 1,150 patients. In this sample, only 10 % of alerts were triggered by an exact match between the drug ordered and allergy listed. Physicians' most common reasons for overriding alerts were “Aware/Will monitor” (55 % ), “Patient does not have this allergy/tolerates” (33 % ), and “Patient taking already” (10 % ). In a stratified random subset of 320 patients (28 % of 1,150) on chart review, 19 (6 % ) experienced ADEs attributed to the overridden drug; of these, 9 (47 % ) were serious. None of the ADEs was considered preventable, because the overrides were deemed clinically justifiable. The degree of completeness of patients' allergy lists was highly variable and generally low in both paper charts and the CPOE system.
Conclusion
Overrides of drug-allergy alerts were common and about 1 in 20 resulted in ADEs, but all of the overrides resulting in ADEs appeared clinically justifiable. The high rate of alert overrides was attributable to frequent nonexact match alerts and infrequent updating of allergy lists. Based on these findings, we have made specific recommendations for increasing the specificity of alerting and thereby improving the clinical utility of the drug allergy alerting system.