Hi Ellen,
I tested the theory a bit further. Assuming that all randomized controlled
trials are classified using the Publication type "Randomized Controlled
Trial" I tested to see how much overall there are between this
classification and the other similar classifications. Here are the results:
Randomized controlled trial[PTYP]
(321677)
Randomized controlled trial[PTYP] AND Controlled Clinical Trial[PTYP]
(4741)
Randomized controlled trial[PTYP] AND Randomized Controlled Trials As
Topic[MeSH] (5408)
Randomized controlled trial[PTYP] AND Random Allocation[MeSH]
(17539)
So there is overlap between the classes even though according to the
definitions of each of these terms, there should be a higher degree of
correlation.
Definitions from MeSH database:
Randomized Controlled Trial [Publication Type]: Work consisting of a
clinical trial that involves at least one test treatment and one control
treatment, concurrent enrollment and follow-up of the test- and
control-treated groups, and in which the treatments to be administered are
selected by a random process, such as the use of a random-numbers table.
Controlled Clinical Trial [Publication Type]: Work consisting of a clinical
trial involving one or more test treatments, at least one control treatment,
specified outcome measures for evaluating the studied intervention, and a
bias-free method for assigning patients to the test treatment. The treatment
may be drugs, devices, or procedures studied for diagnostic, therapeutic, or
prophylactic effectiveness. Control measures include placebos, active
medicine, no-treatment, dosage forms and regimens, historical comparisons,
etc. When randomization using mathematical techniques, such as the use of a
random numbers table, is employed to assign patients to test or control
treatments, the trial is characterized as a RANDOMIZED CONTROLLED TRIAL.
Randomized Controlled Trials as Topic[MeSH]: Clinical trials that involve at
least one test treatment and one control treatment, concurrent enrollment
and follow-up of the test- and control-treated groups, and in which the
treatments to be administered are selected by a random process, such as the
use of a random-numbers table.
Random Allocation[MeSH]: A process involving chance used in therapeutic
trials or other research endeavor for allocating experimental subjects,
human or animal, between treatment and control groups, or among treatment
groups. It may also apply to experiments on inanimate objects.
So either: (1) I am misreading the descriptions since I would consider an
RCT to fall under of these descriptions; (2) the descriptions need an
overhaul to explicitly state when each is used (e.g. actual reporting of
trial results vs. supplementary trial information like protocol, methods,
justification, economic analysis based on RCT, meta-analysis of RCTs, etc.);
(3) the reviewers who are classifying studies are not being consistent in
the way they are using these terms.
For now, I am sticking with the notion that results of randomized trials
would be associated with Randomized controlled trial[PTYP].
Thanks again for your insight and thoughts.
Ahmed
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