When you read about medical research studies, you often see the term "place" used. Since our center is very active in clinical research, the question of placebo comes up a lot from our prospective study volunteers so I though maybe explaining placebo and its role in research would be useful.
A placebo is similar to a blank bullet. A placebo is given for comparison with the "real' treatment." It is a dummy treatment that contains no active substances. The placebo is made to look and taste identical to the drug being tested, so that people in the studies do not know if they are getting the placebo or the "real" treatment. Often it is referred to as a "sugar pill." However, placebo treatments may be given intravenously or into the joint in arthritis studies.
Researchers often talk about the "placebo effect". This is where patients feel better after having a placebo treatment because they expect to feel better.
In a "single blind" study, only the patient doesn't know what they're getting. The investigator (scientist) does know.
In a double-blind study neither the patient nor the investigator knows what the patient is getting. This is a much better design, since an investigator who knows what the patient is getting can convey an unconscious bias towards the patient. In other words, if the investigator knows the patient is getting the "real drug" they might unconsciously bias the patient to having a better response than they ordinarily would. And on the flip side, if the investigator knows the patient is getting a placebo, he or she may have negative expectations for outcome that they unconsciously convey to the patient.
Another phenomenon that many people don't know about is the "nocebo response." This is when a patient gets a negative response to the dummy treatment. In other words, they get worse when they take the sham treatment.
Unfortunately, the word "placebo" has a negative connotation because people don't realize why placebo is used and also because they feel that if they don't get the "drug" that they will become worse.
Placebos are used in research trials because of the phenomenal properties of the brain to believe.
It has been estimated that up to 40 per cent of volunteers enrolled into a clinical research trial for arthritis respond positively to placebo. So it's no surprise that drugs in development need to be compared to a dummy drug to ensure that the positive response is greater than that of placebo. The exact reason why patients respond so well to placebo in arthritis studies may be that they receive extraordinary care while they are participating.
And it's not a phenomenon that's restricted to drugs. For instance, arthroscopic surgery for osteoarthritis of the knee was felt to be a beneficial therapy. However, there have been at least two placebo controlled studies demonstrating that arthroscopic surgery as a treatment for osteoarthritis of the knee is not effective when compared to a sham procedure. Obviously, this is a controversial topic among orthopedists.
Most studies in arthritis give volunteers about a one in four chance of drawing placebo. And many studies which have a placebo arm also have a later phase of the study, where if it is shown that the study drug is effective, that people who received placebo can now receive the study drug "open label". This means they receive the real study drug and they get it for free. Not a bad deal.
Among the biggest reasons for the high cost of medicines is the inability to complete clinical trials in a timely fashion. The most significant hurdle to accomplishing this is patient recruitment into these studies, particularly arthritis studies. And the reason most often given is "I don't want to receive placebo."
If patients understand the nature of placebo and realize that it is not harmful, that there is an excellent chance they'll improve with whatever treatment they get, that they realize that they're getting excellent care, that they may also get free drug later on in the study, and that they often get paid to participate, then it becomes a good idea to at least considering being a clinical trial enrollee.
For more information about participating in an arthritis clinical trial, call the Arthritis and Osteoporosis Center of Maryland at (301) 694-5800 or (888) 71-STUDY.