What is it? Why is it important?
Emergency unblinding (EUB) is the act of revealing the blinded intervention of a participant during study conduct. This might become necessary in order to ensure participant safety including any required clinical management.
For EUB procedures:
- Indicate emergency circumstances that necessitate an EUB
- Define a system that allows for ongoing 24hr EUB (e.g. by phone, scratch cards, sealed envelope, IVRS)
- Allow for rapid identification of participant treatment (e.g. intervention of placebo)
- Allow for unblinding procedures in unexpected circumstances (e.g. electronic system with access to treatment allocation is out of order)
- Describe how to document EUBs
- Define how the Site-INV informs the SP-INV
- Guarantee that blinding is maintained for all other study participants
- Describe conditions where after EUB a participant can remain in the study (e.g. unblinding is not necessarily a reason for study drug discontinuation)
Circumstances that might necessitate an EUB can include:
- Treatment of an AE
- Occurrence of a SUSAR
- A child has accidently ingested the IMP in a participant household
- A request by the DSMB based on study-risk assessment
What do I need to do?
As a SP-INV of a blinded study:
- Describe EUN procedures in an SOP or WI
- Train Site-INV on EUB procedures, including how to document an EUN (e.g. EUN date, time, reason, result, name and role of the person requesting an EUN, name of the blind breaker) and how to notify the SP-INV
- Define other circumstances where unblinding is allowed (premature study termination, interim analysis, statistical analysis at study end)
As a Site-INV:
- Once during study conduct, document and notify the SP-INV regarding any cases of premature unblinding (e.g. both accidental or cases performed as per procedure)
To maintain the overall quality and legitimacy of the study, EUB should only occur under exceptional circumstances.
Where can I get help?
Your local CTU↧ can support you with experienced staff regarding this topic
Basel, Clinical Trials Unit, CTU, dkf.unibas.ch
Bellinzona, Clinical Trials Unit, CTU-EOC, www.ctueoc.ch
Bern, Clinical Trials Unit, CTU, www.ctu.unibe.ch
Geneva, Clinical Research Center, CRC, crc.hug.ch
Lausanne, Clinical Research Center, CRC, www.chuv.ch
St. Gallen, Clinical Trials Unit, CTU, www.kssg.ch
Zürich, Clinical Trials Center, CTC, www.ctc.usz.ch
ICH GCP E6(R2) – see in particular guideline
- 4.7 Randomization procedures and unblinding