The Jadad scale, sometimes known as Jadad scoring or the Oxford quality scoring system, is a procedure to independently assess the methodological quality of a clinical trial. Jadad et al. published a three-point questionnaire that formed the basis for a Jadad score.
Jadad, A.R.; Moore R.A., Carroll D., Jenkinson C., Reynolds D.J.M., Gavaghan D.J., McQuay H.J. (1996). "Assessing the quality of reports of randomized clinical trials: Is blinding necessary?". Controlled Clinical Trials 1996 17 (1): 1–12. PMID 8721797