Cohort discovery

Authorised datasets, query preview, run stages, result groups and evidence.

Prerequisites

An approved protocol version.
A dataset snapshot authorised for the trial, not expired.

Preview

Before running, the preview shows the criteria in plain language, field coverage per criterion, and any criterion that will be Unknown for every record because the field is absent.

Result groups

Potential match — complete: every data-checkable criterion met.
Potential match — data gaps: nothing failed, at least one Unknown.
Excluded by available data: counted, not queued; reason distribution shown.

Reproducibility

A run stores its criteria hash, snapshot, run date and engine version. The same inputs give the same result.