Blinding and Its Types in Research
Published byat August 26th, 2021 , Revised On July 5, 2022
What is Blinding?
Blinding in experimental research is the process in which participants, data analysts, and data collectors are kept unaware of the experiment or study. The objective is to limit biased interpretation of treatment. Binding is mainly carried out in an RCT (randomized controlled trial).
It is usually used in clinical research to keep the patients in the dark as to whether they might require a placebo or not. Placebo is something that might appear to be an active treatment to the participants but does not have any active treatment. A control group is a trial condition not receiving the actual treatment and might serve as a baseline.
Many a time, the name of the treatment is also kept hidden. For instance, patients might have an idea that they are involved in some trials for osteoporosis, but they will have zero information about the name of the brand in the trial.
Why is Blinding Important in Research?
Researchers and data analysts performing specific experiments often expect a particular outcome from it, and intentionally or otherwise, evaluate data in a way that goes well with the preferred hypothesis. It is most significant in subjective trials where skewed outcomes are avoided with blinding.
For instance, blinding can be used in an experiment where pain relief is assessed. If the participants here are aware that they are getting a drug, they will most likely report pain relief than those getting a placebo.
Some benefits associated with blinding in research are:
- Enhances the validity of results in a trial
- Ensures unbiased ascertainment of outcomes
- Makes better the reliability of research
Can you think of another benefit?
Different Types of Blinding
There are three types of blinding:
- Single Blinded Trial
- Double-Blinded Trial
- Triple Blinded Trial
1. Single Blinded Trial:
In a single-blinded trial, blinding or masking of any one group is ensured. Usually, the participant is blinded in a single-blinded trial as they are the ones receiving treatment.
2. Double-Blinded Trial:
In this type of trial, neither the participant knows about the treatment group they are assigned to nor are the researchers interacting with them.
We call this a double-blinded trial because neither you know who is in which group and nor do the participants. Once you are done collecting the sample, you can check the codes on the pills to assess the final data. It is imperative here that the researchers are also unaware of the complete information, which can later help them calculate results without being biased.
3. Triple Blinded Trial:
A triple-blinded trial is where neither the person governing the treatment nor the subject or the person measuring or collecting data is told about the treatment. So, here three parties are blinded:
- The participant
- The researcher
- The data collector
So, is there someone who knows about the details?
Of course, otherwise, it would not be possible to get the experiment done. In a triple-blinded trial, the principal investigator of the research is not blinded and knows about the treatment, participants, and everything about the trial.
When is Blinding Not Possible?
We have discussed how effective it is to use single, double, and triple blinding for different treatments and experiments. But it is not always possible.
In many medical trials, if you plan to fake treatment or use a placebo, the entire thing can go wrong. The treatment sometimes cannot be disguised from either the experimenter or the participant or both. For instance, all the treatments that are physical and can only be performed by physical therapists need to be accurate and mindful.
FAQs About Bliding
Blinding in research, especially in clinical trials, is the process of concealing details about treatment to one or more individuals directly or indirectly associated with the experiment.
In a single-blinded trial, only the participants are unaware of the treatment, while in the latter, both the experimenters and the participants are blinded.
Blinding helps in enhancing the accuracy of an experiment or study. This means the outcomes are less likely to be influenced by various factors not connected to the tested intervention.
This is where three of the major parties that are the participants, the data collectors, and the analysts or researchers have zero knowledge about the experiment.
It is not wise in cases where exposure can only come by interviewing every participant individually. If you apply to the blind in such a situation, the results would be inaccurate, incomplete, and sometimes ruin the whole experiment.