A lot of work goes into designing experiments and clinical trials that yield reliable and unbiased results. Of the many tools that research designers use to achieve this, blinding might be one of the most important, and it’s certainly one that students in clinical research college will encounter frequently in their future careers.
Researchers use blinding to try to minimize or eliminate the effects of subjects’ expectations on a clinical trial, which can otherwise tilt results in favour of a preconceived outcome. With double- and triple-blinding, they also aim to neutralize the biases of the researchers and clinicians conducting the study, who can likewise tilt results in favour of their own expectations, even when those biases are unconscious.
Here’s what students in clinical research college should know.
Single and Double Blinding in Clinical Trials
In a clinical trial, subjects are generally separated into two groups. One group receives the treatment under study—a medication in pill form, for example—and the other receives a placebo treatment, which has no active ingredient.
In a single-blind study, participants are kept unaware of which group they’ve been allocated to. This means that every subject goes through the trial with the same expectations, regardless of whether they’re in the active group or the placebo group.
In a double-blind study, the researchers themselves are also kept unaware of which group a participant has been assigned to, so they do not know whether any given subject is receiving active treatment or a placebo.
Blinding Can Protect Researchers from Accusations of Deception
By withholding from researchers the information that would be necessary to sway results—such as which subject belongs to which group—double and triple-blinding can be useful in protecting the results of a study from accusations of knowing deception.
Students studying for their clinical research diploma can also use blinding to provide protection against the placebo effect and observer bias, two well-documented phenomena which can unconsciously taint the results of a study.
Blinding Is Essential in Overcoming the Placebo Effect
The placebo effect refers to a phenomenon in which a fake treatment improves a subject’s condition despite having no active component, simply because of the subject’s expectation that it will be beneficial. If subjects believe that they’re receiving a medication that heightens their mood or dulls pain, for example, they might experience those effects even if they are only given sugar pills. By using proper blinding procedures, researchers can distinguish between the effects of expectations alone and the effects of the active treatment.
In some cases, it can be difficult to hide from participants which group they’ve been assigned to. This is often the case when testing surgical treatments, or medicinal ingredients that have a very clear taste, smell, or physical effect. Research designers, however, are always developing new ways to effectively blind study participants, even in challenging circumstances.
Graduates of Clinical Research College Can Use Blinding to Reduce Observer Bias
Observer bias is a phenomenon in which the researchers conducting a study can skew the results with their own expectations. Importantly, this can even occur subconsciously. Researchers can unknowingly provide cues indicating how they wish a subject to respond, for example, or they can unintentionally guide subjects towards an expected response. By keeping researchers unaware of which group a subject has been assigned to, however, clinical research college graduates can keep not only subjects’ expectations, but also their own unconscious biases from affecting the results.
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