A clinical trial is a study carried out in human volunteers in order to answer
specific health-related questions. There are two main types of clinical trials:
interventional (also called experimental) and observational. Interventional
trials examine the effects of a particular treatment in a controlled environment.
A controlled environment is one where the investigators try to eliminate factors
that could interfere with the treatment. For example, volunteers who are put
into a controlled environment may be asked to eat the exact same food at the
exact same time of day. In an interventional trial, people are assigned to groups:
one group receives the treatment, and the other does not. Observational trials
look at health issues in a "natural" environment (one that is not
carefully controlled). Rather than assigning people to groups and determining
who will receive a treatment, they observe people who have already chosen whether
to take or not to take a treatment.
The main type of interventional trial is called the randomized controlled trial
(RCT). RCTs are usually designed to compare two groups: an intervention group
and a control group. The intervention group receives the treatment that is being
studied, such as a new medication or a new way of using an existing medication.
The control group gets a placebo (a "sugar pill" with no active ingredients)
or a comparison treatment (usually whichever medication is the current "gold
standard"). Study participants are randomly assigned to their groups, so
that the results of the interventional trial will be directly related to the
treatment that study participants are receiving, and less likely to be influenced
by other factors.
There are a number of different types of observational trials, including cohort
studies, case control studies, case series, and case reports. A cohort study
starts with a large group of people who are taking a particular treatment, and
follows them forward in time to see the results. Results are compared to another
similar group that is not taking the treatment. A case control study starts
with a group of people who have experienced a particular outcome (such as developing
a disease) and looks backward in time to see whether they were exposed to the
treatment being studied or not. A case report is a comprehensive summary of
the treatment received by a particular patient. A case series is a group of
case reports published together as a single paper.
Doctors and researchers generally consider data gathered from a RCT to be the
most reliable, followed by data from cohort studies, case control studies, and
case series. Different types of these clinical trials may be appropriate to
answer certain research questions. For example, sometimes it is more useful
to use a case control study design when studying a treatment side effect that
is rare.
All material copyright MediResource Inc. 1996 – 2024. Terms and conditions of use. The contents herein are for informational purposes only. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Source: www.medbroadcast.com/healthfeature/gethealthfeature/MS-Understanding-Clinical-Trials
There are so many clinical trials done for people with MS that it would be
impossible to keep track of and read all of them. Instead, you need a way to
find the trials that are most important and useful to you. Here are some tips:
- First, focus on what you need to know. Try to think in terms of a
question that you want answered. For example, you may want to know if there
are any new treatments available for MS. In this case, you can narrow things
down by asking if there are any new treatments for the type of MS that you
have (for example, relapsing-remitting). Or, you may want to know whether
you might benefit from a new treatment that you have heard about. In this
case, you may want to ask, "Will this new treatment make me feel less
tired?" or "Will this new treatment improve my ability to function
and carry out my normal daily activities?"
- The next step is to find trials that will help you answer your question.
There are a few different ways to approach this. You could ask your doctor
or pharmacist whether there are any new trials that might help answer the
question you have in mind. You could use a website that reports on clinical
trials in multiple sclerosis, such as www.mssociety.ca. Or you could use a
searchable bibliographic database, such as PubMed, available free of charge
at www.ncbi.nlm.nih.gov/PubMed/. Your local librarian or health professional
may be able to give you tips on how to search PubMed.
You may find a large number of trials that answer your question. In this case,
you will need to find the most relevant, best-quality clinical trials. Narrow
down the list by choosing only:
- the most recently published trials
- randomized controlled trials or review articles
- trials done in humans (not animals)
- trials done in a language that you are able to read
All material copyright MediResource Inc. 1996 – 2024. Terms and conditions of use. The contents herein are for informational purposes only. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Source: www.medbroadcast.com/healthfeature/gethealthfeature/MS-Understanding-Clinical-Trials
The first thing you need to do when reading a trial is to decide whether the
results are valid. In other words, can you trust the results? Here are a few
questions to ask yourself to see if the study results are valid:
- Was the study done in humans, in animals, or in a test tube or laboratory
setting ("in vitro")? Test tube, laboratory, and animal studies
mean that the research is still at an early stage. Studies in humans will
give the best idea of how well the treatment will work for people with MS.
- Was the new treatment compared with a current, well-established treatment,
or with a placebo ("sugar pill" with no active ingredients)?
The best studies will test the treatment against a placebo or another well-established
treatment to see how it compares. Testing against a placebo allows us to see
whether the benefits are due to the new treatment or to other factors. Testing
against an established treatment gives information on whether the new treatment
is better than, the same as, or worse than the established treatment.
- Were the study participants assigned randomly to a treatment group?
This "randomization" helps eliminate bias that may occur if study
personnel were allowed to choose which patients went into which groups.
- Were the treatment groups similar to each other in all ways except for
which treatment they were receiving? During the study, were they treated equally
except for the experimental treatment received? The more similar the groups
and the more similarly they are treated during the study (for all factors
except the treatment being studied), the more likely it will be that any differences
seen between them are due to the treatment and not to other external factors.
- How many people were in the study? The investigators of clinical
trials use the letter "n" to mean "number of people in the
study." In general, the more people (the greater the n), the better.
- How long were the study participants monitored? If the participants
were monitored for only a short time, there is less chance of understanding
the long-term benefits and side effects of the new treatment.
- At the end of the study, were all study participants accounted for?
Did a large number of study volunteers "drop out" of the study?
If so, this may affect the results. The authors should explain how many people
dropped out and what effect, if any, this may have on the results.
- Were the study participants, their doctors, and other "study personnel"
"blind" to treatment? In other words, did anyone know which
treatment the study participants were getting? The best studies will use a
"double-blind" design where neither the study participants nor the
doctors and other study personnel know which treatment the participants are
receiving. This helps eliminate bias due to pre-determined expectations that
people may have from a certain treatment.
If the study meets these criteria, your next step is to check what the study
results were. When reading the study results, it's important to understand how
the treatment effects were measured. This is called an "outcome measure."
MS trials often use a disability rating scale (which rates a person's level
of disability on a numbered scale) as an outcome measure. Look at the difference
between the study treatment and the treatment it was compared to (a placebo
or standard treatment). Did the treatment have better results than what it was
compared to? The study should say whether this difference in results was "statistically
significant." This means that the result is more likely to be due to a
real effect caused by the treatment. A "p-value" is often used to
measure statistical significance, and a p-value of less than 0.05 is usually
considered to be statistically significant.
All material copyright MediResource Inc. 1996 – 2024. Terms and conditions of use. The contents herein are for informational purposes only. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Source: www.medbroadcast.com/healthfeature/gethealthfeature/MS-Understanding-Clinical-Trials
If you've found a study that shows a statistically significant effect for a
new treatment, what does this mean for you? Should you use the new treatment?
What will it do for you, and what are the risks? Here are a few questions you
might ask yourself or discuss with your health professional:
- Do the results apply to me? Whether or not the study results apply
to you depends on a number of factors, including whether the study participants
were similar to you in terms of age, gender, other medical conditions, other
medications taken, and severity of MS. The more similar the study participants
are to you, the more likely it is that the results will apply to you. To judge
this for yourself, look at the criteria that people had to meet in order to
be part of the study. Is there any reason why you would not have been eligible
for the study? If not, chances are good that the results will apply to you.
- What difference would the treatment effect actually make in my life?
For example:
- How long did the benefits last in the study, and would this amount of
time be meaningful to me?
- What side effects and other risks were caused by the study medication?
- How frequent were the side effects?
- Would I be willing and/or able to take these risks or suffer these side
effects?
Talking to your doctor can help apply the study results to your own situation
and put the risks and benefits into perspective. You may want to ask the following
questions:
- What do you think of this study? Is it well designed? Could the results
apply to me?
- Are there any other studies about this medication? Are the results similar
or different?
- What benefits could I gain from this treatment?
- What side effects or other risks could this treatment cause?
- Would you recommend this treatment for me? Why or why not?
- What are my other treatment options at this time?
- Are any new treatment options becoming available soon?
It's important to speak regularly to your doctor about how your treatment is
working for you, and whether any new study results exist that may affect your
treatment.
All material copyright MediResource Inc. 1996 – 2024. Terms and conditions of use. The contents herein are for informational purposes only. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Source: www.medbroadcast.com/healthfeature/gethealthfeature/MS-Understanding-Clinical-Trials
