[Validity parameters of clinical trial and their influence on evidence based medicine conception: a review].
BACKGROUND
The purpose of this study was to review the validity of clinical trials and checklists used to evaluate them in systematic reviews and meta-analyses.


METHODS
We researched Medline and bibliographies of relevant articles with use of keywords and author names.


RESULTS
Methodological choices that have a demonstrated influence on the results of clinical trials include collecting informed consent, comparison of publication with protocol, selection of patients, randomization procedure, number of subjects to include, number lost to follow-up, blinding of patients and evaluation. The type of comparison (with placebo and classic treatment, adjustment of level of significance to the number of measures and number of criteria) and intent-to-treat analysis has a demonstrated influence. The level of this influence is not always precisely determined. In some other fields we didn't find any scientific demonstration even if they have a potential effect.


CONCLUSIONS
The validity of quantitative checklists is low because of lack of scientific demonstration of their relevance.
Forestier
R
R
Centre de recherche rhumatologique et thermale, BP 234, 73100 Aix-Les-Bains cedex, France. romain.forestier@wanadoo.fr
Françon
A
A
Graber-Duvernay
B
B
D002986:Clinical Trials as Topic / Q000592:standards*; D019317:Evidence-Based Medicine