The Drug Allergy History Tool (DAHT): Validation of a Patient-Reported Survey Instrument.

Background: While the reaction history is critical for drug allergy evaluations and is typically self-reported, there is no validated survey instrument to collect drug allergy history from patients.

Objective: To validate a survey instrument that collects patient-reported drug allergy history.

Methods: The Drug Allergy History Tool (DAHT) was revised after three rounds of cognitive testing, with data assessed for reliability, through test-retest comparison, and quality and validity, through a concordance analysis against electronic health record (EHR) allergist documentation. Participants completing testing and surveys were recruited from drug allergy clinics at Massachusetts General Hospital. Primary evaluative measures were percent agreement and Kappa statistic values.

Results: The DAHT was completed by 79 individuals (mean age 49 [SD 17] years, 85% Female, 85% White, 11% Hispanic ethnicity); 29 with single-drug allergy labels and 50 with multiple drug allergy labels. The most common drug allergy labels were penicillins (77%), sulfonamides (32%), cephalosporins (15%), and nonsteroidal anti-inflammatory drugs (8%). DAHT achieved acceptable test-retest reliability (median Kappa = 0.64, median percent agreement = 86%). The DAHT achieved a more complete allergy history than the allergist documentation in the EHR with lower median item uncertainty (21% DAHT vs 79% EHR) with fair concordance (median Kappa = 0.21, median percent agreement = 67%) between the two data sources.

Conclusion: The DAHT is a reliable and valid source of patient-reported allergy information. This tool can be used in clinical care and clinical research to obtain standardized patient reported drug allergy history.