How do I repair a screening log that lost its exclusion reasons?

Rebuild exclusion reasons by re-screening each excluded record against your stated eligibility criteria and its source record, then repopulate the log, flag uncertain entries, and document the repair in the screening workflow.

Reconstruct the reasons

1. Freeze the current log and export a working copy. List every record marked excluded with its identifier, the criteria version applied at the time, and the reviewer who made the call. Expected result: a complete list of records needing a reason.
2. Re-screen each excluded record against the eligibility criteria in force when it was excluded. Record the specific criterion it failed and the part of the source record that shows the failure. Expected result: a reason tied to a criterion and a source location for each record.
3. Flag any record where the source record does not clearly show the failure, where the criteria version is unknown, or where two reviewers would likely disagree. Mark these as uncertain and route them to a second reviewer. Expected result: a short list of entries needing a decision.
4. Repopulate the log with the reconstructed reason, the criterion reference, the source location, and a note that the reason was reconstructed rather than recorded at screening time. Expected result: a log that distinguishes original from reconstructed entries.
5. Document the repair: what was lost, how reasons were rebuilt, which criteria version was used, and how uncertain entries were resolved. PRISMA 2020 reporting covers the methods used and the studies found and included, so the repair note belongs with your methods record.
6. Update the screening workflow so reasons are captured at the point of exclusion and stored with the record. Add a check that no record can be marked excluded without a reason and criterion reference.

What to keep

The Cochrane Handbook describes documenting searches and managing records for systematic reviews; keep the reconstructed log alongside the search documentation so the exclusion trail stays traceable. Where a reason cannot be recovered from the criteria and source record, leave it flagged as unresolved and record the next verification step, such as retrieving the full text or asking the original reviewer.