With all the interest in evidence-based dentistry ("How Do You Define and See Evidence-Based Dentistry?" Question of the Month, June 2003), it would be well to look at the evidence. The past medical and dental literature has certainly given us pause to be professionally critical of the source of the evidence.
Thirty years ago, Moser observed that "the volume of pertinent new information that finally becomes available each yearthe meaty stuff that a physician needs to know in order to provide optimal care to his patientsis not overwhelming ... the problem lies in separating the wheat from the incredible amount of chaff."1
Twenty-three years ago, Sheehan2 noted that "2/3 of the studies appearing in the best medical journals contain unwarranted conclusions."
Ten years ago, Janowitz3 noted the perpetuation of published medical errors.
Davis and Ben-Sasson4 questioned 10 years ago whether "medical journals suppress information."
Walker5 noted that "since meta-analysis cannot pull up a single datum, the summary can be at once exhaustive and paradoxically superficial."
Auerbach,6 in a 1999 Dental Economics article summarizing an original article previously published, stated, "It is difficult to document the need for evidence-based dentistry. In reality, we implicitly use the concept of evidence-based dentistry in every procedure we do."
Most disturbingly, Rennie7 cites Gotzsche,8 who "found 44 [multiple] publications of 31 of the clinical trials, 20 trials published twice, 10 three times and one trial five times, with the overall proportion of multiple publications being at least 18 percent. The fact that the data had been published elsewhere was not noted in 32 of the 44 [articles]. Indeed, in about half of them, the first author and the number of authors were different, and in half there were important discrepancies between the various versions of the same trial. Gotzsche pointed out that some cases were so difficult to detect that in a meta analysis they might have been mistaken for separate trials."
So, here we are, 30 years later, facing Dr. Mosers problem of separating the wheat from the chaff.
McLellan9 wrote an article on the accuracy of reference in journals entitled, "Trust, but Verify." That appears to be sound advice, to which Dr. Moser would have agreed, or so it seems to me.