Quality of Documentation of Contrast Agent Allergies in Electronic Health Records

Abstract

Purpose: To describe and appraise contrast agent allergy documentation in the electronic health record (EHR).

Methods: We systematically identified medical imaging drugs and class terms in an integrated EHR allergy repository for patients seen at a large health care system between 2000 and 2013. Structured and free-text contrast allergy records were normalized and categorized by inciting agent and nature of adverse reaction. Allergen records were evaluated by their level of specificity. Reaction records were evaluated by whether the reaction was known or unknown and whether known reactions would be categorized as allergic-like or physiologic.

Results: Among 2.7 million patients, we identified 36,144 patients (1.3%) with at least one of 40,669 contrast allergy records associated with 49,000 reactions. Contrast allergens were more likely than other allergens to be entered as free text (15.2% versus 6.3%; odds ratio 2.69, 95% confidence interval 2.61-2.76). There were 1,305 unique contrast allergen records, which we grouped into 141 concepts. Most contrast allergen records were ambiguous contrast concepts (69.1%), rather than imaging modality-specific class terms (19.4%) or specific contrast agents (11.5%). Contrast reactions were occasionally entered as free text (24.8%), which together with structured entries were grouped into 183 concepts. A known reaction was documented in 71.8% of cases; however, 12.2% were non-allergic-like reactions.

Conclusion: Contrast allergy records in EHRs are diverse and commonly low quality. Continued EHR enhancements and training are needed to support contrast allergy documentation to facilitate improved patient care and medical research.

Keywords: Contrast media; drug hypersensitivity; electronic health records; information storage and retrieval; natural language processing.