The '''Jadad scale''' sometimes known as '''Jadad scoring''' is a procedure to independently assess the quality of a clinical trial It is the most widely used such assessment in the world
and as of 2008 has been cited in over 3000 scientific papers
The Jadad scale
is named after Alejandro Jadad , a Colombian physician
who in 1996 was working as a Research Fellow at the Oxford Pain Relief Unit Nuffield Department of Anaesthetics at the University of Oxford Jadad and his team
outlined their views of the effectiveness
on published studies in a 1996 paper
in the Journal of Controlled Clinical Trials
Clinical trials exist for the purpose of collecting
data on the efficacy of forms of medical treatment The treatment might be a new drug a medical device
or a preventative regime
Clinical trial protocols vary considerably depending on the nature
of the treatment under investigation but typically researchers gather a group of volunteers subject them to the treatment and after a defined time
period assess them for improvements in health
that the randomised controlled trial was of great importance for the advancement of medicinal science describing it in a 2007 book as "one of the simplest most powerful and revolutionary forms of research"
In an appendix to their 1996 paper
Jadad et al
published a three-point questionnaire that formed the basis for a Jadad score
[yes or a no Each yes would score a single point each no zero points; there were to be no fractional points The questions were as follows:]
- Was the study described as randomized?
- Was the study described as double blind?
- Was there a description of withdrawals and dropouts?
Additional points were given if:
- The method of randomisation was described in the paper and that method was appropriate
- The method of blinding was described and it was appropriate
Points would however be deducted if:
- The method of randomisation was described but was inappropriate
- The method of blinding was described but was inappropriate
A paper reporting the results of clinical trial could therefore receive a Jadad score of between zero and five The Jadad scale is sometimes described as a five-point scale though there are only three questions