an in print or rather in press article is not a reliable source it has to be published and referenceable where others can get a hold of it the errors in the abstract of the online version shows that it is obviously a pre publication version and can't count by the way not even the toc for the april issue of caswj has been revealed so we just have your word for it that it is appearing at all the new developments book is so new that no libraries yet have it but a look at the toc online as well as the article title it looks like it is a review article not a report of original research so if you are hanging your hat on this references well the best that can be said is that jury is still out and ddp is still not been subjected to the judgment of the scientific community we can revisit this when the casjw article is actually published until then we cannot say that ddp is evidence based much less that is accepted by the scientific community of course you may have other evidence but you have yet to cite any