Strengthening spontaneous reporting-based signal detection during a pandemic with cases from electronic health...

During the COVID-19 pandemic, vaccines were rapidly developed, but some potential adverse drug reactions (ADRs) were still undetected at the time of market authorization. The analysis of ADR reports received through the spontaneous reporting system (SRS) remains the cornerstone for safety signal detection. A limitation is that reporting ADRs is voluntary. In this study the added value of electronic health records (EHRs) was explored as an additional source to spontaneous reports, to strengthen safety signal detection concerning COVID-19 vaccines.

The electronic health record adverse event (EHR-AE) search method was developed to enable targeted searches in EHRs using a natural language processing (NLP) tool with text-mining functionalities to identify additional potential cases. Searches were performed in EHRs of two Dutch hospitals concerning several established and non-established (potential) ADRs associated with COVID-19 vaccines. Identified cases were reported to Lareb and analyzed in addition to spontaneous reports for safety signal detection.

Thirteen searches were conducted between January 1, 2023, and December 1, 2023, concerning different (potential) ADRs associated with COVID-19 vaccines. For 6 associations at least 1 case was identified, resulting in a total of 41 additional cases reported to Lareb. These cases contributed to the detection of two safety signals concerning COVID-19 vaccines. Two safety signals could have been detected approximately 18 and 2 months earlier, if the EHR-AE method had been implemented during the COVID-19 pandemic.

The EHR-AE search method can strengthen and accelerate the signal detection process for potential ADRs associated with COVID-19 vaccination. Future studies should expand to more hospitals, aiming to further evaluate the added value of the method, including for which drug-ADR associations the EHR-AE search method is most beneficial.