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Double Blind Vs Single blind Study

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(@jordankayal)
Posts: 82
Trusted Member
 
Posted by: @smitshah

I cant really think Why is it needed to use double blind study since I think single blind i.e. only patient blind must work.In double blind both Investigator and patient will not know about the drug and doctor will have to identify who is given what which would lengthen the process of trial and I think if investigator knows it shouldn't affect the outcome of study

For example: If a research group is developing an Alzhimer's drug and they are in clinical phase how would it affect the investigator if he knows that a patient is given placibo or a drug to cure Alzhimer's.

Whats's your point in this and if you think double blind are better and you provide some example.

In a double blind study, the investigator doesn't necessarily need to be blinded. Typically, I think it's necessary to blind the patient so they can't influence the outcome of the study. If they knew they were getting a placebo rather than the actual treatment, they most likely wouldn't show any improvements, which would defeat the purpose of the study. However, another group that could be blinded are the doctors. It may not make much of a difference in pharmaceutical trials, but in a surgery where the doctor can either use one design or another (i.e. a new design vs an old design for the same company, a design from one company vs a design from another, etc.) where both products look very similar, this could be a method for the Investigator to evaluate a 1 to 1 comparison of the products. This would eliminate any partiality the surgeon may have to a particular product, since they would perform their procedures the same way regardless of the product being used since they wouldn't know the difference. 

 
Posted : 26/10/2019 11:10 am
(@jordankayal)
Posts: 82
Trusted Member
 
Posted by: @smitshah

I cant really think Why is it needed to use double blind study since I think single blind i.e. only patient blind must work.In double blind both Investigator and patient will not know about the drug and doctor will have to identify who is given what which would lengthen the process of trial and I think if investigator knows it shouldn't affect the outcome of study

For example: If a research group is developing an Alzhimer's drug and they are in clinical phase how would it affect the investigator if he knows that a patient is given placibo or a drug to cure Alzhimer's.

Whats's your point in this and if you think double blind are better and you provide some example.

In a double blind study, the investigator doesn't necessarily need to be blinded. Typically, I think it's necessary to blind the patient so they can't influence the outcome of the study. If they knew they were getting a placebo rather than the actual treatment, they most likely wouldn't show any improvements, which would defeat the purpose of the study. However, another group that could be blinded are the doctors. It may not make much of a difference in pharmaceutical trials, but in a surgery where the doctor can either use one design or another (i.e. a new design vs an old design for the same company, a design from one company vs a design from another, etc.) where both products look very similar, this could be a method for the Investigator to evaluate a 1 to 1 comparison of the products. This would eliminate any partiality the surgeon may have to a particular product, since they would perform their procedures the same way regardless of the product being used since they wouldn't know the difference. 

 
Posted : 26/10/2019 11:11 am
(@yifan-tao)
Posts: 39
Eminent Member
 

In psychology, a single-blind study is a type of experiment or clinical trial in which the experimenters are aware of which subjects are receiving the treatment or independent variable, but the participants of the study are not. A study in which both the experimenters and participants are unaware of who is receiving the independent variable and who is not is known as a double-blind study. A double blind study is one in which neither the participants nor the experimenters know who is receiving a particular treatment. This procedure is utilized to prevent bias in research results. Double blind studies are particularly useful for preventing bias due to demand characteristics or the placebo effect. For example, in a single blind study, when the researchers are informed, they will inadvertently affect the patients' feelings, resulting in a placebo effect, which will lead to the untruth of the whole process. Therefore, in this case, the advantages of double-blind experiment are highlighted, because both parties do not know who used the drug, and the results are more real and reliable.

 
Posted : 27/10/2019 12:56 am
(@sameer-rana)
Posts: 78
Trusted Member
 

For starters, I believe a double blind study is definitely better for clinical trials that involve the testing of things like a new medicine or pill. The reason for this is that it removes any additional bias that could have affected the results of the trial on behalf of those administering the treatment such as a doctor. An example of how a doctor could be the cause of bias in a single blind study is that they could purposely or by accident express to the patient what result they believe will occur from the treatment that is being administered to them. For instance, if a doctor knows a patient is receiving a placebo and they don’t believe it will result in any positive outcome, they could directly or indirectly hint this belief of theirs to the patient. As Dr. Simon mentioned in his lecture, the mind is a powerful thing and this belief expressed to the patient could result in them believing and expressing that there was no positive outcome as a result of the trial. On the contrary, if both the doctor and the patient were unaware whether a placebo was being administered, there is a possibility that a positive outcome could have resulted because the patient believed the result would be positive for them. Overall, double blind studies are important and better indicators of a higher level of clinical research when there is a high chance of bias that could be expressed on the part of those administering the treatment under examination.

This post was modified 4 years ago by sameer-rana
 
Posted : 27/10/2019 1:53 pm
(@jl959)
Posts: 77
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A double blind study provides more assurance that the results of the study are as accurate and unbias as possible. For example, this type of study can be conducted by randomly assigning treatment of oral placebo sugar pills and pills containing the actual medication. While the investigator will try to mask their knowledge of issuing placebo pills to the control group, he/she may unconsciously affect each group through reinterpretation effect. Since the investigator knows which pill should be deemed effective, he/she will have expectations of each subject's response. Through reinterpretation effect, patients may stress their improvements and downplay their negative symptoms in order to please the physician/investigator (and match the investigator's expectations). A double blind study will also eliminate observer bias, where investigators tend to observe what they want or expect to observe. Observer bias may lead the investigator to exaggerate the positive and negative response from the subjects issued the medication and downplay the response of the control group issued the placebo. Also, it won't be a difficult to conduct a double blind study with medications that are identical in appearance and delivery method.

 
Posted : 27/10/2019 7:55 pm
(@parth0796)
Posts: 36
Eminent Member
 

I feel that a double blind study should be preferred over just a single blind study because ideally the patient not knowing if he has been given a placebo or not is important as the investigator knowing will not affect the patients psychology and the result will be apt but sometimes it can be a possibility that if the doctor/investigator knows he can be partial and the outcome might not be that accurate but doing the double blind will surely give better results than single blind.

 
Posted : 27/10/2019 8:28 pm
(@darshannayee)
Posts: 40
Eminent Member
 

Based on the lecture I think double blind referee to the doctor and patient not knowing which medication is real and which is dummy medication. This study can avoid possibility of doctor influencing the result by being bias. Results obtained by this methods are close to being accurate then someone influencing the result which will deviate results. If the doctor is soft and wants all of his patients to be cured so he will give them the actual medication instead of varying between real and dummy medication which will compromise the data as you want know the effects of placebo in your study.

 
Posted : 27/10/2019 8:54 pm
(@christoph)
Posts: 44
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A double blind study help to eliminate bias of doctors participating. It is within the realm possibility to have a doctor whom may be willing to influence a study out come for monetary gain. The doctor could have accessed to data and use it intentionally modify result for the a particular study group.
For example giving less efficacy to the control group so as make as to delay a drug appearance on the market. Or giving more efficacy to the control group so as to increase the drugs appearance on market.
There really is no reason to believe that a doctor like any other human is not succeptible to the impetus of falsifying data to derive gain

 
Posted : 27/10/2019 11:08 pm
(@rowel2202)
Posts: 51
Trusted Member
 

Double blind studies, in my opinion, are more accurate since they provide a valid baseline for the experiment. The talk used the double blind multi-center research as an example. The talk used the double blind multi-center research as an example. Dr. Simon demonstrates how a doctor's skill influenced the study, and because it was a multi-center, double-blind trial, you can argue that the baselines were all fairly similar because patient and surgeon bias was removed in this situation. If this trial were single blind, the surgeon bias would have to be taken into consideration, and the statistical significance of comparing several sites would be reduced. Applying the same logic to the Alzheimer's disease example, if any of the investigators have a financial incentive for the drug to succeed, this could introduce bias into the study that would not exist if it was conducted under double blind conditions and the investigators were unaware of the placebo vs. experimental dose.

 
Posted : 24/06/2021 8:44 pm
(@mejefferson)
Posts: 48
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Posted by: @smitshah

I cant really think Why is it needed to use double blind study since I think single blind i.e. only patient blind must work.In double blind both Investigator and patient will not know about the drug and doctor will have to identify who is given what which would lengthen the process of trial and I think if investigator knows it shouldn't affect the outcome of study

For example: If a research group is developing an Alzhimer's drug and they are in clinical phase how would it affect the investigator if he knows that a patient is given placibo or a drug to cure Alzhimer's.

Whats's your point in this and if you think double blind are better and you provide some example.

In single blind studies, only the particpants are blinded whereas in a double blind study both the participants and experimenters and blinded. I personally think that single blinded studies are better because you have more data to work with opposed to guessing who, what, where, when, why and how. Common, simple double blind studies occur with taste testing. I think this is a great moment to do a double blind study because when it comes to testing and trying food, it usually is a mental thing on whether something is spicy, sweet, salty, etc. In a sense, people can think what they want when it comes to food so having the experimenters blinded as well can assist them with knowing what samples were provided. Another example of a double blind study is with medicines in which I think these should be tested using a single blinded study. When testing with medicines you need to be able to track everything without any hesitations. 

 
Posted : 19/09/2021 7:16 pm
(@sfrancis)
Posts: 42
Eminent Member
 

Double blind studies provide an extra veil to protect the integrity of the study. Having both the participants and the medical professionals blind to who is receiving which treatment. This yields any unintentional biases that the medical professionals could unknowingly convey to the study participants. A randomized double blind study using a placebo is the best study design to use to determine if the new drug is effective.

 
Posted : 24/09/2021 10:12 pm
(@rajamharrison)
Posts: 46
Eminent Member
 
Posted by: @smitshah

I cant really think Why is it needed to use double blind study since I think single blind i.e. only patient blind must work.In double blind both Investigator and patient will not know about the drug and doctor will have to identify who is given what which would lengthen the process of trial and I think if investigator knows it shouldn't affect the outcome of study

For example: If a research group is developing an Alzhimer's drug and they are in clinical phase how would it affect the investigator if he knows that a patient is given placibo or a drug to cure Alzhimer's.

Whats's your point in this and if you think double blind are better and you provide some example.

I think single blind is effective, but I understand the use of double blind studies.  I believe they use double blind studies to promote impartiality.  Some researchers can become so attached to their research that can start to see positive effects of the drug that is not really there.  The researchers can become bias.  With the double blind study, they do not know who got the drug and who got the placebo, so they can look at each person as if each one got the drug and study their effects with an impartial eye.  This way they are able to actually study each patient and see if they have any positive effects from the drug or not.

 
Posted : 25/09/2021 11:42 am
(@anthonynjit)
Posts: 78
Trusted Member
 
Posted by: @smitshah

I cant really think Why is it needed to use double blind study since I think single blind i.e. only patient blind must work.In double blind both Investigator and patient will not know about the drug and doctor will have to identify who is given what which would lengthen the process of trial and I think if investigator knows it shouldn't affect the outcome of study

For example: If a research group is developing an Alzhimer's drug and they are in clinical phase how would it affect the investigator if he knows that a patient is given placibo or a drug to cure Alzhimer's.

Whats's your point in this and if you think double blind are better and you provide some example.

I agree with your initial confusion as to why a double-blind is necessary/preferred in some instances. It appears to be an unnecessary step that can possibly complicate or expose your trial to knowing error via the handling of the treatment by an unbiased person. However, double-blind studies ensure that there are no possible biases during the administration of the treatment. Therefore, results can be fully trusted to be without either administrator or patient bias to the treatment they receive. While I don't believe a single-blind study is worse than a double blind, if possible performing a double-blind study ensures the utmost integrity of your results.

 
Posted : 19/10/2021 4:51 pm
(@ridmehta)
Posts: 79
Trusted Member
 

Like many people in this thread, I also acknowledge the many benefits of a double blind study. As unfortunate as it is, bias does impact humans whether they are aware of it or not. This also applies in medicine as many reports have been made of certain healthcare providers giving better treatment to certain ethnic groups or genders over others. By having a double blind study, specific demographics and backgrounds won't be favored over others and the study can provide a healthy comparison between the data points.

 
Posted : 19/10/2021 8:00 pm
(@cruzdonato)
Posts: 30
Trusted Member
 

In a single-blind study, the investigator knows what they are administering while the patient does not whereas in a double-blind study, both the investigator and the patient are unaware if a drug or a placebo is being used. Double-blind studies are tailored to eliminate bias from the doctor or investigator administering the drug. While investigators may not intend to reveal whether they are giving the real drug or a placebo, a patient may read an investigator's reactions or pick up on context clues in their dialogue that could affect the study's outcome. Investigators may also input their personal beliefs about the study which could also affect the outcome.  I also feel that a double-blind study also helps at evaluating not only how the patient is affected, but also how a doctor interacts with the patient and the device/drug being tested.

 
Posted : 20/10/2021 11:01 am
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