Is there any literature on how documented allergies and adverse drug reactions are affected during transitions between EHR systems, particularly regarding data migration accuracy and the potential for previously resolved or inactivated allergy or adverse reaction records to be reactivated in the new EHR.

Comment by InpharmD Researcher

The published literature on the impact of allergy and adverse drug reaction documentation during electronic health record (EHR)–to–EHR transitions is limited but consistent. Across these sources, allergy data are repeatedly identified as a high-risk element during transitions due to reliance on free-text entries, variable documentation standards, and limited semantic interoperability, often requiring manual review or re-entry. Reported issues include incomplete transfer, loss or alteration of reaction details, clinician verification burden, and reappearance of previously resolved or de-labeled allergies due to data update gaps or reconciliation failures. Additional evidence describes instances in which critical allergy information was not carried forward at all, as well as one case in which downgraded allergy labels were reacquired in the new EHR, with documented patient harm. Overall, the literature indicates that EHR transitions can materially affect the accuracy and persistence of allergy and adverse reaction documentation, underscoring the need for structured data, validation, and post-transition monitoring.

("electronic health record" OR EHR) AND ("data migration" OR transition OR conversion) AND ("drug allergy" OR allergies OR "adverse drug reaction") AND (documentation OR accuracy OR reconciliation OR relabel OR reactivate)

Background

Reviews addressing the challenges of electronic health record (EHR)-to-EHR transitions and data migration highlight major patient safety concerns, noting that allergy and adverse drug reaction documentation is particularly vulnerable due to free-text entries, inconsistent standards, and semantic interoperability limitations. Across the literature reviewed, allergy data were frequently handled via manual abstraction, partial electronic conversion, or hybrid approaches rather than full automated migration. Reported issues included incomplete transfer, need for clinician re-entry or verification, mapping difficulties during electronic conversion, and reliance on continued access to legacy systems for verification. Case studies demonstrated that active allergies were prioritized for transfer, while inactive or historical data were often left in legacy systems, and that allergy data required careful validation regardless of migration strategy. Overall, both reviews emphasized a need for explicit planning, validation, and post-transition monitoring of allergy data to mitigate patient safety risks. [1], [2]

A 2020 retrospective chart review describes a system-wide transition from a legacy EHR to Epic at Vanderbilt University Medical Center. Investigators reviewed 511 patients evaluated in a dedicated drug allergy clinic between March 5, 2014, and November 1, 2017, to assess the accuracy of revised drug allergy label transfer across EHR systems. A total of over 3 million allergy labels were migrated; approximately 226,000 labels were not codable and required manual reconciliation. Overall, 79/511 patients (15.4%) had discrepancies between EHRs, involving 114 specific drug allergy labels. Of these, 15/114 (13%) were reacquired after having been removed in the legacy EHR, 69/114 (61%) were lost, and 30/114 (26%) had altered or incomplete reaction details. Forty of the 114 discrepant labels (35%) suggested potentially severe reactions, including anaphylaxis, Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN), or drug reaction with eosinophilia and systemic symptoms (DRESS), affecting 28/511 patients (5%); 8/28 (29%) had subsequent encounters in the new EHR in which allergy review occurred but discrepancies persisted (Table 1). Seven patients who had been de-labeled in the 6 weeks prior to the EHR transition reverted to their pre-testing allergy labels post-transition, including penicillin (n= 9), sulfonamide (n= 4), fluoroquinolone (n= 1), and cephalosporin (n= 1) labels, with penicillin accounting for 45% of re-labeled cases. Re-labeling was observed for 19 medications after the EHR transition compared with 14 medications in the pre-transition period. Reacquired labels were attributed to post–go-live data update limitations, extensive reliance on free-text allergy entries in the legacy system, and incomplete reconciliation processes. No adverse clinical events were identified. The authors emphasize the need for standardized documentation, structured data entry, and validation of allergy records to prioritize patient safety. [3], [4]

Literature Review

A search of the published medical literature revealed 2 studies investigating the researchable question:

Level of evidence

D - Case reports or unreliable data Read more→

Please see Tables 1-2 for your response.

Drug name	Former EHR description	New EHR description	Background of most recent drug allergy reviewer
allopurinol	Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN)	Gastrointestinal intolerance	Unknown title*
minocycline	Stevens-Johnson syndrome (SJS) Avoid doxycycline (listed as a separate allergy) Avoid tetracycline (listed as a separate allergy)	High severity rash Changed to doxycycline No longer listed	Unknown title
ceftriaxone	Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) Recommend avoidance of cefepime and cefotaxime	No cephalosporins listed as an allergy	Pharmacist
amoxicillin	Drug reaction with eosinophilia and systemic symptoms (DRESS)	Gastrointestinal intolerance	Unknown title
ondansetron	Anaphylaxis and skin prick test positive	"per pt"	Registered Nurse
ceftriaxone	Anaphylaxis and skin prick test positive	ceftriaxone no longer listed Description was listed under the drug name "other" along with 2 additional reaction descriptions	Physician
*Unknown title includes user roles defined as medical assistants, technicians, or no information. Responsible for 37% of all the drug allergy labels entered in the new electronic health record (EHR).

References:
[1] Adapted from: Rukasin CRF, Henderlight S, Bosen T, Nelson SD, Phillips EJ. Implications of electronic health record transition on drug allergy labels. J Allergy Clin Immunol Pract. 2020;8(2):764-766. doi:10.1016/j.jaip.2019.07.017

DRESSed for Failure
Design	Case report
Case presentation	A 60-year-old woman who used a wheelchair presented to the emergency department with right-hand cellulitis and an uncomplicated urinary tract infection. She was treated with intravenous ceftriaxone and discharged on oral cephalexin. One week later, she returned critically ill with hypotension, altered mental status, and an erythematous, desquamating rash, requiring intensive care admission and treatment for presumed sepsis. Dermatology consultation and chart review identified a prior diagnosis of cephalexin-associated drug rash with eosinophilia and systemic symptoms (DRESS); high-dose corticosteroids were administered with rapid clinical improvement, and the patient was discharged at baseline. Root cause analysis showed that the prior cephalexin-induced DRESS was documented only as an allergy in the legacy electronic health record (EHR) and was not carried forward during a transition to a new EHR in which allergy lists were rebuilt manually. Despite subsequent ambulatory encounters after the transition, the cephalexin allergy was not re-entered, and the patient’s non-verbal status and reliance on caregivers limited history verification.
Study Author Conclusions	EHR implementations are increasing nationally, and transitions between EHR systems present distinct challenges related to data migration and mapping. Drug allergy information is a critical data element that should be prioritized for transfer during EHR-to-EHR transitions. Educating clinicians about transition-related safety risks may increase vigilance and help reduce prescribing errors.

References:
[1] Abramson E, Kaushal R. DRESSed for failure. Agency for Healthcare Research and Quality. Published September 1, 2013. Accessed January 16, 2026. https://psnet.ahrq.gov/web-mm/dressed-failure