This is a ready-to-use log for capturing every unblinding event in a blinded trial, emergency, accidental, or planned, in a controlled, sponsor-segregated location. It has two parts: a detailed per-event record with the full field set an inspector expects, and a master register for tracking every event across the study so the end-of-study reconciliation described in the blinding article has something to reconcile against. Replace every <<FILL: ...>> placeholder. This content is educational reference, not legal or regulatory advice.
Header
| Field | Entry |
|---|---|
| Log ID | <<FILL: LOG-ID>> |
| Protocol number / title | <<FILL>> |
| Storage location and access restriction | <<FILL: e.g. segregated PV-controlled folder, access list attached>> |
| Log owner | <<FILL: role, e.g. Pharmacovigilance Lead / Clinical Trial Lead>> |
Field definitions and instructions
| Field | Format | Required | Who completes it | When |
|---|---|---|---|---|
| Subject ID | Site-subject identifier | Yes | Investigator or delegate (emergency); sponsor (planned) | At the time of the break |
| Randomization number | As assigned by IRT | Yes | Same as above | At the time of the break |
| Date/time of break | Date and time with explicit time zone | Yes | Same as above | At the time of the break |
| Break type | Emergency / Accidental / Planned (analysis or database lock) | Yes | Log owner | At entry |
| Broken by | Name and role | Yes | Same as above | At the time of the break |
| Authorized by | Name and role, or “self-authorized (emergency)“ | Yes | Same as above | At the time of the break |
| Reason / justification | Free text | Yes | Same as above | At the time of the break |
| Method | IRT / manual envelope / scratch-off / key release procedure | Yes | Same as above | At the time of the break |
| Treatment revealed | Recorded only in a PV- or firewall-controlled field, never in a field visible to the conduct team | Yes, in the controlled field only | PV or unblinded statistician, as applicable | At the time of the break |
| PV notified | Yes/No, date/time notified | Yes for emergency and accidental breaks | PV or notifying party | Within the defined notification window |
| Conduct team informed | What the conduct team was told (event occurred only, never the assignment) | Yes | Log owner | At the time of the break |
| Subject outcome | Free text; continued/discontinued and follow-up | Yes for emergency and accidental breaks | Investigator | At resolution |
| Reconciliation | Who confirmed the entry against source/IRT, and when | Yes | CRA or QA | At next review, and at study end |
Retain each record per the trial’s records retention schedule; the master register and every individual record are retained together.
Unblinding event record (per event)
| Field | Entry |
|---|---|
| Study / protocol | <<FILL>> |
| Site | <<FILL>> |
| Subject ID | <<FILL>> |
| Randomization number | <<FILL>> |
| Break type | <<FILL: Emergency / Accidental / Planned>> |
| Date/time of break (with time zone) | <<FILL>> |
| Broken by | <<FILL: name, role>> |
| Authorized by | <<FILL>> |
| Reason / clinical justification | <<FILL>> |
| Method | <<FILL: IRT / manual / key release>> |
| Treatment revealed | <<FILL: recorded in controlled field only>> |
| PV notified | <<FILL: Yes/No, date/time>> |
| Conduct team informed of assignment | <<FILL: No, told only that a break occurred>> |
| Subject outcome | <<FILL>> |
| Reconciliation | <<FILL: who confirmed, date>> |
Master unblinding register (all events, study to date)
| Event ID | Subject ID | Break type | Date/time | Method | PV notified | Reconciled |
|---|---|---|---|---|---|---|
<<FILL>> | <<FILL>> | <<FILL>> | <<FILL>> | <<FILL>> | <<FILL>> | <<FILL: Yes/No>> |
Acceptance criteria
- Every field in the per-event record is complete; a blank “reason” or “method” field is a finding, not an oversight to fix later.
- The treatment-revealed field is populated only in the controlled location and never appears in any export or report the conduct team can access.
- Every emergency and accidental break shows a PV notification entry with a date/time.
- Every event in the master register reconciles to a per-event record, and every per-event record appears in the register; the two never diverge.
- At study end, the register reconciles against the IRT audit trail, any manual envelopes or scratch-off panels used, and the final key-release record.
Signoff
| Role | Name | Signature | Date |
|---|---|---|---|
| Log owner | <<FILL>> | ||
| QA (periodic review) | <<FILL>> |
References
ICH E6(R2) Good Clinical Practice and ICH E6(R3) Principles and Annex 1, integrity of randomization and blinding and the audit-trail expectation for unblinding events. ICH E2A, expedited safety reporting timelines relevant to the PV-notified field. 21 CFR Part 11 / EU GMP Annex 11, audit trail requirements applicable to an electronic version of this log.
Confirm the current version of each reference before issue.
Filled specimen
The following is an original worked example, distinct from any example in the source article, showing the level of detail expected. The protocol, site, and subject are illustrative.
A male subject enrolled in a blinded trial of an investigational agent with known teratogenic potential in animal models reports, through his site contact, that his partner has a confirmed pregnancy dated to approximately three weeks after his most recent dose. The investigator determines that knowing the subject’s treatment assignment is necessary to counsel appropriately on fetal risk and to decide whether to interrupt or discontinue dosing, and breaks the blind through the IRT the same day.
| Field | Entry |
|---|---|
| Study / protocol | DEF-118 |
| Site | 007 |
| Subject ID | 007-0056 |
| Randomization number | R-0439 |
| Break type | Emergency |
| Date/time of break (with time zone) | 2026-04-02 10:05 GMT |
| Broken by | Investigator name, role: Principal Investigator |
| Authorized by | Self-authorized (treating investigator, emergency) |
| Reason / clinical justification | Partner pregnancy reported, conception approximately 3 weeks post-dose; treatment knowledge required to counsel on fetal risk and decide on dose interruption |
| Method | IRT emergency-unblinding function |
| Treatment revealed | Recorded in PV-controlled field; suppressed from conduct-team view |
| PV notified | Yes, sponsor safety mailbox, 2026-04-02 10:14 GMT |
| Conduct team informed of assignment | No (told only that a break occurred) |
| Subject outcome | Dosing interrupted pending further evaluation; partner referred for prenatal counseling; case followed per the trial’s pregnancy-reporting procedure |
| Reconciliation | IRT log vs source confirmed by CRA at visit on 2026-04-09 |
The reviewer checking this record confirms the same things every time: the reason on file actually supports the necessity standard, the time of the break maps to when the report was received, the conduct team’s record shows only that a break occurred, and PV received the assignment and opened the pregnancy-reporting pathway on the same day.
Common inspection findings this log prevents
- A break that happened with no corresponding log entry at all, discovered only through the IRT audit trail during a later review.
- A log entry missing the time zone, making it impossible to confirm the break happened when the justification claims.
- The treatment-revealed field visible in a report or export the conduct team can see.
- A master register that does not reconcile with the individual event records, or with the IRT audit trail at study end.
How to adapt this log
- Set the storage location and access restriction in the header before the first subject is randomized, and confirm it in your IRT and eTMF access reviews.
- Decide whether this log is maintained in the IRT itself (preferred, since it self-populates from the audit trail) or as a separate controlled document, and state which in the header.
- Add a row to the master register for every event, including accidental and planned unblinding, not emergency breaks alone.
- Confirm every regulation in the references against the current published version before issue.