A recent commenter asked the following question:
If you are a clinical researcher, how do you test a treatment for recurring body-wide pain and extreme fatigue that has lasted more than a year? How do you use science to test whether X treatment works? What measurement(s) do you make pre- and post-treatment to produce a clinical study that supports or indicates the underlying reality?
In this hypothetical, let’s say the reality is that the treatment produces significant reductions in the body-wide pain and fatigue in 98% the afflicted. How do you produce a legitimate, science-based study that supports this?
For someone who is suffering, the details of designing a clinical study may not be the first thing on their mind. But for researchers, it must be. Clinicians must then be able to assimilate relevant data to use in treating their patients.
The first task in looking at this question is, "what is the question?" In this case, we need a disease or syndrome with a useful operational definition. Since the commenter hasn't given us one, we'll choose "fibromyalgia". This syndrome is difficult but not impossible to study. It's difficult because it is syndromic; we can define a list of signs and symptoms and create an operational definition, but we cannot pathologically define the illness.
In this case, we can measure exactly what the commenter asks. We can choose an intervention, say, a sleep aid called Miraculum, and design a randomized controlled trial. Patients can be recruited, randomized to placebo or Miraculum, and outcomes of interest can be measured. There are many tools to measure these outcomes including visual analog pain scales and quality of life measures. The numbers can be crunched and interpreted, and voila, we have an answer (and usually more questions as well).
I hope this helps our curious commenter.