Towards automating systematic reviews on immunization using an advanced natural language processing–based extraction system
Bibliographic record
Abstract
Evidence-informed decision making is based on the premise that the entirety of information on a topic is collected and analyzed. Systematic reviews allow for data from different studies to be rigorously assessed according to PICO principles (population, intervention, control, outcomes). However, conducting a systematic review is generally a slow process that is a significant drain on resources. The fundamental problem is that the current approach to creating a systematic review cannot scale to meet the challenges resulting from the massive body of unstructured evidence. For this reason, the Public Health Agency of Canada has been examining the automation of different stages of evidence synthesis to increase efficiencies. In this article, we present an overview of an initial version of a novel machine learning-based system that is powered by recent advances in natural language processing (NLP), such as BioBERT, with further optimizations completed using a new immunization-specific document database. The resulting optimized NLP model at the core of this system is able to identify and extract PICO-related fields from publications on immunization with an average accuracy of 88% across five classes of text. Functionality is provided through a straightforward web interface.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.029 | 0.095 |
| Meta-epidemiology (narrow) | 0.003 | 0.002 |
| Meta-epidemiology (broad) | 0.003 | 0.005 |
| Bibliometrics | 0.011 | 0.009 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.008 | 0.006 |
| Open science | 0.003 | 0.005 |
| Research integrity | 0.003 | 0.003 |
| Insufficient payload (model declined to judge) | 0.012 | 0.009 |
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".