An open-label trial, or open trial, is a type of clinical trial in which information is not withheld from trial participants. In particular, both the researchers and participants know which treatment is being administered. This contrasts with a blinded experiment , where information is withheld  to reduce bias. Open-label trials may be appropriate for comparing two very similar treatments to determine which is most effective . An open-label trial may be unavoidable under some circumstances , such as comparing the effectiveness of a medication to intensive physical therapy sessions . An open-label trial may still be randomized. Open-label trials may also be uncontrolled ( i.e. without a placebo group), with all participants receiving the same treatment.
An open-label trial, or open trial, is a type of clinical trial in which information is not withheld from trial participants. In particular, both the researchers and participants know which treatment is being administered. This contrasts with a double-blinded trial , where information is withheld both from the researchers and the participants to reduce bias. Open-label trials may be appropriate for comparing two similar treatments to determine which is most effective , such as a comparison of different prescription anticoagulants or possible relief from symptoms of some disorders when a placebo is given . An open-label trial may still be randomized. Open-label trials may also be uncontrolled ( without a placebo group), with all participants receiving the same treatment.
R
blinded experiment
double-blinded trial
A
both from the researchers and the participants
D
very
D
. An open-label trial may be unavoidable under some circumstances
R
comparing the effectiveness of a medication to intensive physical therapy sessions
a comparison of different prescription anticoagulants or possible relief from symptoms of some disorders when a placebo is given
D
i.e.