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(MS) Study (from 1994) showing different results when physicians were blinded vs not blinded

Dolphin

Senior Member
Messages
17,567
I'm just reading a book which mentioned this example

The impact of blinding on the results of a randomized, placebo-controlled multiple sclerosis clinical trial.
Noseworthy JH1, Ebers GC, Vandervoort MK, Farquhar RE, Yetisir E, Roberts R.

Neurology. 1994 Jan;44(1):16-20.

Author information

Abstract

In the randomized, placebo-controlled, physician-blinded Canadian cooperative trial of cyclophosphamide and plasma exchange, neither active treatment regimens (group I: i.v. cyclophosphamide and prednisone; group II: weekly plasma exchange, oral cyclophosphamide, and prednisone) were superior to placebo (group III: sham plasma exchange and placebo medications) using the blinded, evaluating neurologists' assessments of disease course (primary analysis).

All patients were examined by both a blinded and an unblinded neurologist at each assessment in this trial.

We compared the blinded and unblinded neurologists' judgment of treatment response and analyzed the clinical behavior of patients who correctly guessed their treatment.

The unblinded (but not the blinded) neurologists' scores demonstrated an apparent treatment benefit at 6, 12, and 24 months for the group II patients (not group I or placebo; p < 0.05, two-tailed).

There were no significant differences in the time to treatment failure or in the proportions of patients improved, stable, or worse between the group II and group III patients who correctly guessed their treatment assignments and those who did not.

Physician blinding prevented an erroneous conclusion about treatment efficacy (false positive, type 1 error).
 

Cheshire

Senior Member
Messages
1,129
If I understood correctly a kind of reverse placebo effect targetting the neurologists. Really interesting
 

alex3619

Senior Member
Messages
13,810
Location
Logan, Queensland, Australia
he was not a drug addict. Cocaine was not considered to be an addictive drug back then.
Not by the standards of the day, but either sustained cocaine use is addictive, or it isn't, though there would be individual variance in addiction tendency. By today's standards he was a regular drug user, though my understanding is this was not life long. Did he ever give it up? I don't recall.