Cohort Representation and Exploration
Bibliographic record
Abstract
The abundant availability of health-care data calls for effective analysis methods which help medical experts gain a better understanding of their data. While the focus has been largely on prediction, "representation" and "exploration" of health-care data have received little attention. In this paper, we introduce CORE, a framework for representing and exploring patient cohorts. Obtaining a readable and succinct representation of health data of a cohort is challenging because cohorts often consist of hundreds of patients whose medical actions are of various types and occur at different points in time. We extend the Needleman-Wunsch algorithm for sequence matching to handle temporal sequences, and propose "trajectory families", a customized index to efficiently compare and aggregate patient trajectories into a cohort representation. We define cohort exploration as finding similar cohorts to a given cohort. This problem is challenging because the potential number of similar cohorts is huge. We propose a two-staged approach based on limiting the search space to "contrast cohorts" and then computing their similarity to the given cohort. To speed up cohort similarity computation, we use "event sets" in the same spirit as the double dictionary encoding proposed for keyword search. We run qualitative and quantitative experiments on real data to explore the efficiency and usefulness of CORE. We show that CORE representations reduce time-to-insight from hours to seconds and help medical experts find insights better than state-of-the-art Visual Analytics tools.
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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 | 0.003 | 0.016 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.002 |
| Bibliometrics | 0.003 | 0.003 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.002 | 0.003 |
| Open science | 0.002 | 0.004 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.005 | 0.001 |
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".