(ASPOT10) Evaluation of drug hypersensitivity reactions documented in a new coded and structured hypersensitivity documentation tool with de-labeling function: A retrospective cohort study

Background: Improper documentation of drug hypersensitivities (DHs) in electronic health records can lead to adverse drug events. Therefore, we implemented a new structured, coded hypersensitivity (HS) documentation tool with de-labeling feature at our university hospital in May 2022.

Objectives: To evaluate the quality of documented DHs after implementation of the new HS documentation tool in clinical practice.

Methods: We conducted an observational, retrospective cohort study at a Belgian university hospital. All patients with at least one encounter between May 2022 and October 2023 were included in our DH cohort. Data from both the new coded HS tool, which included all drugs as exposures, and the previous free-text allergy tool were analyzed for completeness and accuracy as quality outcome measures. As all DH fields are mandatory to fill, completeness requires entries from the previous tool to be converted to the new tool, signalizations entered mainly by nurses to be validated by a physician or clinical pharmacist, or a formal indication of no DH. Accuracy is adherence to the correct way of entering DHs into the new tool, such as avoiding free-text entries for coded terms. Descriptive statistics and Chi-square test were used for statistical analysis.

Results: In the specified period, 2449 of 305,096 patients (0.8%) with a hospital encounter had documented DH. Of these, median age was 53 years (IQR = 33) and 1798 (73.4%) were females. This corresponded to 2916 DHs in the new tool, as a patient can have multiple entries. Free-text DHs from the previous tool (15,033) need to be converted, which was done for 158 DHs (1.1%). Moreover, 230,293 patients (75.5%) lack DH information or a formal indication of no DH. Of the 2916 DHs, 1655 (56.8%) were entered by physicians. Penicillin exposure (as a group) accounted for most DHs (n = 508, 30.7%), while 108 entries (6.5%) had non-coded allergens. These 1655 allergens corresponded to 2078 reactions, with the most common reaction after ‘unknown’ (n=632, 30.4%) being rash (n = 151, 7.3%), while 178 reactions (8.6%) were non-coded. Remaining 1197 DHs (41.0%) were signalizations, and 64 DHs (2.2%) were inactivated. Incomplete DH documentation was observed in 291,192 patients (95.4%), with conversion or validation of DHs required in 1299 of 2449 patients (53.0%), while 255 patients (10.4%) had inaccurate DH documentation. Females have a significantly higher odds of DH (OR = 2.12, 95% CI 1.92-2.34, χ2 = 228.1, df = 1). However, this is based on retrospective data in a hospital, limiting generalizability.

Conclusions: The new documentation tool has not yet reached its full potential. Training users and optimizing the tool may improve DH documentation and patient safety. Implementing an efficient alerting system is needed for immediate benefit of complete and accurate DH documentation.