Kevin,
With a randomized clinical trial, the study design gives you the best chance
of concluding that the result is due to the experimental intervention, not a
confounder. By randomizing the population to experimental group(s) and a
control group, the two groups should be very comparable in age, gender,
ethnicity, weight, health status, etc. If you found a difference, and did not
randomize, it is possible that the experimental group did better because they
were 10 years younger, for example. A control group shows that the
intervention did something. For example, if you tested the strength of an
experimental group, put them on an exercise program, and tested them again 2
months later, you would have data on the change. What would have happened if
you hadn't done anything? The control group tells you that. Through
randomization, both groups should be comparable at the first test. At 2
months, your hypothesis would state that the experimental group had a strength
increase, and the control group would be the same. You could have only the
experimental group improve--hypothesis supported. If, however, both groups
improved, something else that you weren't controlling for was involved, and
your program might not be it. For example, the control group, knowing the
purpose of the study, decided exercise was a good idea and joined the gym, two
months produced a natural strength change through daily activity, equipment
problems in testing, etc. If you had only tested the experimental group, you
would not know that people improved in two months without your help.
This is brief, and entire chapters are written on this topic. I hope it helps.
If you have another question, or this is not clear, let me know, and I'll try
to explain more.
Renee
kevin reese wrote:
>
> Dear Lists
>
> WITH APOLOGIES FOR CROSS REFERENCING
>
> I am curious to know why the RCT is considered a Gold Standard when
> conducting therapy research. Any thoughts ?
>
> Kevin Reese PT UK.
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