How I would assess whether liberation therapy worked or not?

We need to do a randomised double-blind controlled trial (RCT).

A RCT is a scientific experiment; study subjects who have CCSVI need to be randomly allocated to receive liberation therapy (angioplasty and/or stents) compared to sham or placebo therapy (the same procedure but during which no angioplasty is performed or stent inserted). It will be very important that the person undergoing the study procedure does not know what is happening to them. Therefore the neuro-radiologist who does the procedure must not let on what is happening to them. 

After randomisation, the two groups of subjects need to followed up and assessed in exactly the same way, by a neurologist who does not know what procedure they have had. 

Double-blind means that both the subject and the assessing neurologist does not know what procedure the subject has had; this is critical if we want to be confident in the results of the trial. 

The purpose of randomisation is to minimises bias by balancing both known and unknown factors that may affect the outcome. 

I suggest the outcome of the trial should be defined as sustained improvement or stabilisation in disability at 6 or 12 months; in other words if a greater proportion of subjects who received liberation therapy have a stabilisation or improvement in their disability compared to the subjects who have sham treatment we could then conclude that liberation therapy is effective. 

There are many other factors that need to be considered when designing this study; for example how many subjects need to be enrolled, we call this the power of the study, and for how long should study subjects be followed. The latter is usually determined by the measure we use to assess subjects, in the case of disability we use the expanded disability status scale (EDSS). There are also safety considerations and methods to analyse the data to be taken into account. 

The following flowchart describes the steps of a RCT. 


"Any bets on what the outcome of this trial will be?"

Additional reading; RCTliberation therapyangioplastyvascular stents, placebo, EDSS