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Approximately 2,000 MS-related research papers are published every year - that's about seven studies each day.
Often the results of one study seem to contradict another study. How do you make sense of these scientific findings? The following information is to help put the scientific findings you encounter in context.
Whether or not a study can be considered credible and scientifically sound depends on many factors, including the type of study conducted, the expertise of the researchers, the statistical analyses used and the rigour and quality of the external independent review of the results.
Many hypotheses regarding possible treatments for MS begin in the lab. In these studies, the treatments are often assessed at a very basic level through the use of cells and cultures as well as an experimental, animal model of MS called experimental allergic encephalomyelitis (EAE) in laboratory rodents. These studies allow for a preliminary evaluation of the possible benefits of a treatment, as well as some idea of the safety and risks of that treatment. If the study is promising, it might move after further study into clinical trials.
Clinical trials are research studies that involve testing or studying a treatment in people to see if it is safe and effective. Each phase of a clinical trial follows a protocol and has a specific goal. The information gathered in a trial is used to build knowledge about the new treatment and support the subsequent phases of the research process.
Purpose | Study Design | Participants | |
Phase I | To determine safety and tolerability of treatment. | Usually open-label (both the researchers and participants know what the participant is taking as a medication). | 20-80 |
Phase II | To look more closely at safety and efficacy and how the treatment affects the body. | Usually includes control and non-control groups are often double-blind. | 100-300 |
Phase III | Last step before treatment is submitted to Health Canada. Done to confirm treatment's efficacy, monitor side effects, and compare it commonly used treatments. | Can last up to five years or more and are randomized, double-blind and placebo-controlled trials. | 1000-3000 (multi-centre) |
Phase IV | Once Health Canada has approved treatment, this study is often done to identify further information about risks, benefits, side effects, and optimal use. | Several hundred- several thousand |
A control is the standard against which experimental treatments are evaluated. In Phase II and III clinical trials, one group of patients will be given an experimental treatment, while the control group is given either a standard treatment for the illness or a placebo. A control is part of the criteria of evidence-based medicine.
A placebo is an 'inert' pill, liquid, or powder with no active ingredients. In phase II and III trials, experimental treatments are compared with placebos to assess the experimental treatment's efficacy and safety.
A sham procedure is a placebo form of a procedure. A trial participant may receive a 'sham' or 'fake' surgery, injection or other medical procedure, so that there is a control group.
The placebo effect is a scientifically recognized, measurable reality. There are measurable changes that occur in the brain when someone is given a placebo that they expect or hope will benefit them. The effect tends to be the greatest in symptoms with a subjective component, such as pain, but it can affect physical function too.