A Pilot Report on Extracting Symptom Onset Date and Time From Clinical Notes in Patients Presenting With Chest Pain
Bibliographic record
Abstract
The timing of clinical events is important information in understanding disease progression and its critical context and relationship to treatment and patient outcomes. However, time information documentation in the electronic health record (EHR) is inconsistent, hindering its utility in research and clinical care. In research where event timing is crucial, such as symptom onset in acute coronary syndrome, automated tools can expedite data collection, reducing the reliance on labor-intensive manual reviews. We aimed to apply natural language processing (NLP) methods for extracting date and time (DateTime) information from free-text EHR clinical notes. Two off-the-shelf NLP pipelines, parsedatetime and regular expression ( regex ), were pilot tested on 71 annotated clinical notes: History and Physical (n=49), Emergency Department Screening (n=3), and Triage Notes (n=19). Parsedatetime identified correct DateTime information in 36 notes (50.7%) with an F1-score of 0.31 (low performance), while regex failed to produce any accurate outputs. Despite parsedatetime outperforming regex , its performance remains inadequate. Both approaches required significant refinement and customization to improve efficacy. To optimize automated DateTime extraction, future research should focus on advanced rule-based NLP methods capable of handling complex narratives. Consistent time documentation by clinicians, adhering to standardized formats, remains essential for improving the downstream usability of EHR data.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.007 | 0.040 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.002 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".