A Multimodal Pipeline for Clinical Data Extraction: Applying Vision-Language Models to Scans of Transfusion Reaction Reports
Henning Schäfer, Cynthia S. Schmidt, Johannes Wutzkowsky, Kamil Lorek, Lea Reinartz, Johannes Rückert, Christian Temme, Britta Böckmann, Peter A. Horn, Christoph M. Friedrich
TL;DR
The paper addresses the persistence of paper-based transfusion reaction reporting by introducing an open-source multimodal pipeline that automates checkbox data extraction from scanned forms. It combines a YOLOv8-based checkbox detector with two extraction pathways—OCR plus Levenshtein matching and a vision-language model prompting approach— and validates performance against gold-standard annual reports from 2017 to 2024. Results show that the VLM-based method achieves higher precision, recall, and overall category-mapping accuracy than the OCR-based baseline, with barcode detection also yielding high accuracies; the pipeline significantly reduces manual data entry while maintaining reliability. The approach is multilingual, adaptable to other checkbox-rich documents, and designed for self-hosted deployment, offering a scalable, open-source framework for improving regulatory reporting and data-driven decision-making in healthcare.
Abstract
Despite the growing adoption of electronic health records, many processes still rely on paper documents, reflecting the heterogeneous real-world conditions in which healthcare is delivered. The manual transcription process is time-consuming and prone to errors when transferring paper-based data to digital formats. To streamline this workflow, this study presents an open-source pipeline that extracts and categorizes checkbox data from scanned documents. Demonstrated on transfusion reaction reports, the design supports adaptation to other checkbox-rich document types. The proposed method integrates checkbox detection, multilingual optical character recognition (OCR) and multilingual vision-language models (VLMs). The pipeline achieves high precision and recall compared against annually compiled gold-standards from 2017 to 2024. The result is a reduction in administrative workload and accurate regulatory reporting. The open-source availability of this pipeline encourages self-hosted parsing of checkbox forms.
