I believe that if a clinical study is to occur the study should occur as a double blind study. Any bias that could alter the outcome of the study should be avoided at all cost. It is normal to want to trust the researchers or doctors to not tell the patient who is trial and who is control but their is still room for human error. A simple slip up of a patients classification can ruin that patients statistical relevance to the whole study. A double blind study stops this from occurring. If the researcher or doctor is not able to tell the patient what they are receiving there is less room for error to occur.

I would have to disagree with smithshah. I believe double-blind studies are important! The two type of blinded studies are single-blind and double-blind. Single-blind is when the patient doesn't know what drug/group is being given to them (either the experimental group or control group). While in a double-blind study the researchers/doctors and patients are both unaware of what group the patients are placed into. If we start to analyze the advantages and disadvantages of each system the double-blind system is believed to guarantee a better objectivity because it avoids any possibility of biases or skew the results by tipping off the patients about which pill the patient is taking. Since there is such a high need and pressure for drug companies and researched to generate positive results, hence why dishonestly in results arises, and why a double-blind clinical study is ideal for the integrity of the results of the clinical studies and limits the chance of criticism.

An exam of a double-blind clinical study is an assessment of patient outcome with the Minnesota Living with Heart Failure questionnaire: Reliability and validity during a randomized, double-blind, placebo-controlled trial of pimobendan. The goal of this clinical trail is to determine the reliability and validity of a patient outcome questionnaire for chronic heart failure, a randomized, double-blind, placebo-controlled, 3-month trial of pimobendan, an investigational medication with inotropic and vasodilator activities, was performed. Evaluated were 198 ambulatory patients with primarily New York Heart Association (NYHA) class III heart failure from 20 referral centers.( http://www.sciencedirect.com/science/article/pii/0002870392909866)

I think double blind test is better. Since some scientists are dishonest, they often have pressures comes from billion dollar drug companies and the fight of research grants, so they want to have positive results. Therefore they may give the drugs to the patients who have the better chance of recovery and even manipulate results, try to show the research in a better light.
And double blind test can avoid this.

I think it depends on the study matter and double blind is not always necessary. Yet there are certain cases where double blind would be preferable. It is used to prevent research outcomes from being influenced by the placebo effect or observer bias. If a researcher knows that certain patients are getting the actual drug (lets say for Alzheimers), they may subconsciously emphasize certain questions or invest more time to help the patient score improved outcomes. Also there is research that shows that when a researcher invests more faith in the patient, the patient can somehow detect this and this feeling boosts their outcomes. Thus to prevent any subconscious (or conscious) bias, it is better to use a computer or double blind method when there are high stakes.

Putting blinds on a study makes its results subject to less bias and outside influence. The more blinds there are the more representative of normal the data will become, and thus the more believable. With each addition of a blind, less people become liabilities. In single blind, the researchers are liabilities only. In double blind, the statisticians/data analysts are the only liabilities. With each person you take off the liability list, it neutralizes the effect of their bias on the data. It also stops them from influencing which patient receives what treatment or giving preferential treatment to a patient. It even mitigates damage from accidental slip-ups, like telling a patient they are on the placebo. Studies in which the researchers have little emotional attachment to the subjects do not require multiple blinds as much because there is less motivation to tamper with the protocol. A general rule of thumb is that more blinds = less data fouling.

In my opinion, a double-blind study is always better when possible. Working with a patient, especially in long clinical trials can sometimes cause a connection between the patient and the experimenter, creating bias. It’s just human nature sometimes to, even without meaning to, have a certain bias towards someone over another. The double blind study obviously prevent that from happening and would provide more accurate results, which in the end would benefit everyone.

I understand that in a single blind study the investigator knows what is being used on the subject and that can cause a bias but in the double blind study who knows what is being given to the patients? That might be an easy question but I am still confused as to who would know what is being given to who. For example if you have the pill you want to test and the placebo pill who would know which patient got which pill if both the investigator and the patient both do not know.But besides this question I can see why a double blind study is more accurate. The experiment results will be better if there is less bias. It is always good to make sure the patient does not know what they are taking so they do not change the results depending on what they feel. I also believe that the patients should also not have a bias so that should be determined before the experiment. This can help the results be more accurate.

I would go with a Double Blind study whenever possible. Utilizing a single blind study can lead to researcher's bias. Researcher's Bias is when the researcher looks for data that confirms a specific outcome that is beneficial to them. By removing this element, you add more validity to your study in my opinion.

Double blinds are good, but triple blinds are better. The patient may have the placebo effect, the researcher may unwittingly indicate the type of treatment on way or the other, and the analyst may select data based on what they expect to see. The placebo effect is a well-documented phenomenon. The researcher may have bias, but one issue that I haven't seen raised is that they may signal the patient that they are being treated on way or the other. This would then start the placebo effect. This all would skew the data towards one outcome over the actual results. When the analyst doesn't know what he/she is looking at, they can sift through and analyze the data without imparting their own bias onto the results. When removing outliers or scaling results, they cannot change the data to fit a certain outcome if they don't have an idea of what the outcome should be. The more blinds, the more assurance the study has of being impartial and removed of human bias towards a certain outcome.

A single blind experiment only the participants does not know whether they are part of the treatment or the control group, whereas in a double-blind experiment both the participant and the experimenter are kept in the dark as to who is in the treatment and who is in the group. Double blind study serves as a standard by which all the studies are judged since it minimizes both the potential patient biases and potential assessor biases. A blind experiment would reduce the risk of bias from the effect which gives a genuine baseline for the research which ultimately allows to have a realistic statistical comparison.

I think the point of a double blind study is that it eliminates any biases. The researchers and doctors might expect or wish for a certain outcome and might influence the distribution of the drug/therapy, making it biased. In order to prevent situations like this, a double blind study would be used. The randomized the study is, the experiment becomes more credible and reliable.

Although not as important as single-blind study in my opinion, double-blind study does indeed present added assurance to the accuracy of the trial results at the end. Because the investigators who interact with the subjects will not be aware of who receives the real drug and who receives the placebo, there is absolutely no possibility for an investigator to become biased. For instance, an investigator may feel obligated to give a patient the real drug when he or she is given the placebo. Or perhaps the investigator, for whatever reason, does not want a particular subject to take the real drug and provides the placebo instead. As you mentioned however, it does add more time and even risk to determine which subjects had which treatment to obtain the results. There is added risk because there is a higher chance that certain subjects may have been believed to consume the drug when they actually had the placebo or vice versa. All in all, for trials that require extremely accurate results and trial is conducted properly, establishing a double-blind method would be beneficial.

It's not that confusing actually, it will be easier to understand this rule when you think of this as a clinical researcher. One of the most important reasons is that there is always an overall objective you wish to confirm in the beginning, that will cause the observer-expectancy bias if you know which group is which. That means there will be some confounding factors such as the evaluation on the degree of the disease, the treatment and dosage control, and the knowledge of specific contradictions, that must have been artificially manipulated whether knowingly or unknowingly to distort the outcome in the process.

In a single blind experiment, the subjects don't know if they are the experiment test group or members of the control group but the tester knows. The subjects are not told their identities in the experiment. The subject receiving the medicine would not know if they were receiving the drug or the placebo. In the double blind experiment, both the tester and the subjects are blinded. Both the tester and the subject doesn’t know the identities in the experiment. Neither the patients receiving the treatment nor the doctor distributing the medicine would know if the patients were receiving the drug or the placebo. Since the tester does not know which group received the placebo or the experimental drug means that the risk of conscious and unconscious observer bias is reduced, making the study more accurate. Usually researchers go with randomized single blind and double blind experiment setup to prevent any type of bias in the results.

In a single blind experiment, the doctor is able to use their biases to determine who is administered the drug and who is administered the placebo. In this case, the patient's medical history, background, and situation may impact on the outcomes of the experiment. In a double blind experiment, the patient and the doctor are unaware of the actual treatment being administered, allowing for the experiment to be random. This also allows for the results/analytics to be taken without prior knowledge if the patient received the placebo or the actual drug. This will remove any expectations that the doctors might have from the patient and how they would react to the drug/placebo.