Hsieh TC, Kuperman GJ, Jaggi T, Hojnowski-Diaz P, Fiskio J, Williams DH, et al. Characteristics and consequences of drug allergy alert overrides in a computerized physician order entry system. J Am Med Inform Assoc. 2004 Nov-Dec; 11(6): 482-91
The researchers reviewed a total of 7,761 drug allergy alerts generated by the CPOE system at Brigham and Women’s Hospital in a 3 month period. In total, 80% (6,182) of the alerts were overridden by the physician. The goals of the study included categorizing the reasons for the overrides, identifying when the overrides led to adverse drug events and to suggest methods to improve drug allergy alerting protocols.
A patient’s allergy list is entered into the system by the admitting physician upon admission of a patient into the hospital. When medications are ordered, the system compares the drug with the drugs on the allergy list and issues a “definite allergy” alert if the medication is an exact match or is in the same class as a drug on the allergy list. The system will also alert for “possible allergy” reactions based on known cross-reaction drug mappings. The system requires the clinician to enter a free-form text reason for overriding the alert. The researchers classified these reasons as: “Patient does not have this allergy/Tolerates,” “Aware/Will monitor,” “Patient taking already,” “Desensitization protocol,” and “Other.”
A total of 1,150 patients had overridden alerts. The study found that “90% of the overridden alerts were triggered by nonexact drug/allergy matches, in which the drug and allergy had structural similarities or were in the same family but were not identical.” The most frequent reason given for overrides was “Aware/Will monitor” (55%).
A total of 19 ADEs were identified as being caused by the administration of an overridden drug. However, none of these ADEs were considered by the physician reviewers as being preventable because the potential clinical benefits were judged to outweigh the risks of a serious allergic reaction.
The researchers concluded that “the high override rate appears to be attributable primarily to excessive and inappropriate alerting." Among their recommendations were making a distinction between drug allergies and drug sensitivities/intolerances. Interruptive alerts should be displayed only for true allergic reactions (not sensitivities) and the system should make serious or life-threatening warnings readily distinguishable from less dangerous warnings. Warnings of sensitivities should be displayed in a non-interruptive manner.
Other recommendations included generating alerts only when there is an exact drug match, generating no alert for an order for sulfonamide non-antibiotics when the allergy list indicates a “sulfa” allergy and improving the maintenance of patients’ allergy lists.
COMMENT: As noted by the researchers, it is important for healthcare organizations to include review of the overridden alerts as part of their quality improvement program and take actions to reduce the percentage of overridden alerts by fine-tuning the alerting protocols.
