Extraction features: complete breakdown

What extraction stores

Extraction rows store structured values for included or eligible studies. They can represent baseline variables, outcome measurements, and study-design or study-characteristics fields.

• Study and group/arm identifiers.
• Outcome or variable names.
• Numerical values such as mean, SD, events, totals, sample size, confidence intervals, p-values, and related fields where the template supports them.
• Units, timepoints, subgroup paths, notes, and custom field values.
• Source page, quote, span identifiers, bounding boxes, PDF hash, and provenance metadata.

PDF handling

• Direct PDF upload is available.
• Open-access PDF fetch can be used where the project has the required feature access and the source is available.
• PDF access follows project membership and role permissions.
• The evidence viewer keeps the report beside the extraction workspace.

Evidence viewer

The evidence viewer helps reviewers inspect the source report while extracting. Use it to locate the table, paragraph, or figure where a value came from.

• Available text, page, region, and table information can support evidence capture.
• Selected text can be sent to extraction fields where the workflow supports it.
• Project-wide PDF search is premium-gated and only shown when enabled.
• Source quotes and pages should be captured for values that affect analysis or manuscript tables.

Extraction grid

• Edit baseline, outcome, and study-design rows.
• Add, update, or remove rows where supported.
• Track source/provenance at the field level.
• Use validation to catch missing or inconsistent values.
• Use version history and restore controls when changes need audit review.

Harmonization helpers

Coventra includes helpers for common evidence-synthesis conversions, but users must verify the result.

• Unit harmonization.
• IQR, range, SE, CI, and p-value conversions where the input shape supports them.
• Median-to-mean conversion in analysis workflows.
• Outcome synthesis and cluster naming support where configured.

Blind dual extraction

Blind extraction support allows independent extraction drafts, conflict comparison, resolution, and reviewer completion summaries. Use it when the protocol requires independent duplicate extraction.

AI-assisted extraction boundaries

Premium projects can use optional study-characteristics suggestions. Suggestions are not final data. The reviewer must inspect, accept, edit, or reject them.

Data freeze

Data freeze creates a final-analysis snapshot boundary. Use it when extraction and validation are complete enough for final analysis and manuscript exports.

• Freeze after resolving major extraction conflicts.
• Freeze after validation warnings are reviewed.
• Keep a note of what changed if data are edited after a freeze.