The Jadad scoring system is a widely used method of rating RCTs for basic methodological rigour. However it seems to be inadequately structured to meaningfully discern the methodological standard of meditation trials. For instance, while all trials might be randomised, only a minority described randomisation methods and few use the term “double blind”.
The blinding process in meditation trials is complex since it involves blinding of participants, raters, instructors, statisticians and other investigators.
It also demands that the comparator intervention is properly able to control for non-specific effects. Many trials feature some of these steps and others actually feature them all. And yet the Jadad score only applies one point for this crucial but complex and multifaceted factor. Similarly, very few trials described drop-outs.
The Jadad score of the studies in my review mostly ranged between 0 and 2. Trials with high scores did not seem to be much better designed than trials with lower scores. Thus the Jadad system does not usefully differentiate between trials with a methodology of a sufficient standard to discern effects specific to meditation, and those that do not have such a methodology. Despite evaluating other methodological rating systems none were appropriately orientated to be useful in discerning meditation research.