What blinding hides, and from whom
In blinded studies, only unblinded roles see treatment arms, block sizes, the randomization list and the unblinded kit list. Everyone else sees "Treatment assignment blinded", kit numbers without arms, and totals instead of per-arm counts.
Who sees treatment arms
| Blinded roles | Unblinded roles | |
|---|---|---|
| Roles | Most roles, including the Study Owner, investigators, coordinators, CRAs, data managers and sponsors | Unblinded Administrator, Unblinded Statistician, Medical Monitor, Depot Manager |
| Participant page | "Treatment assignment blinded" plus the randomization number | The arm and its code, and the block |
| Inventory | Kit numbers only, supply totals | Arm column, per-arm supply, the unblinded kit list |
| Exports and audit trail | No arm columns; arm-revealing audit details are masked | Unblinded exports with a justification and password |
In open-label studies everyone sees the arm, marked Open label, and the Casebook can be filtered by arm. Arm-specific visit schedules can reveal the arm to anyone who sees the schedule, so plan them carefully (arm-specific visits).
Change the blinding level
The level (open label, single blind or double blind) is set in Settings > General > Blinding. Once participants are randomized, an open-label study cannot become blinded. Changing a blinded study to open-label needs a reason and your electronic signature, and everyone can then see the arms. In an emergency, investigators can unblind a single participant.
Questions
Is blinding only hidden in the screens?
No. Blinded roles never receive treatment arm values at all, so they cannot appear in their downloads either. Read more about blinding.
Was this guide helpful?
Related guides
Still need help?
Email support@capture.study or use the contact form. Tell us the study name, what you were trying to do and the exact message on screen; a screenshot helps.
Please never send participant names, contact details or health information to support.