Efficacy of Glucosamine and Chondroitin for Treatment of Osteoarthritis—Reply

In Reply: Dr Mautone expresses concern that we did not give credit to some trials for ITT analyses even when this was stated in the text of our article. In Reichelt's study, the ITT results for the primary outcome measure are not reported—the trials by Rovati and Bucsi gave no indication of an ITT approach. For the study by Bourgeois et al, we would like to acknowledge that this was indeed misclassified in the table in our article, as Mautone points out.

We also agree with Mautone that the support of the pharmaceutical industry is critical in advancing research in therapeutic compounds. Of course, this poses a dilemma in a meta-analysis because it has been shown repeatedly that industry involvement in clinical trials is more frequently associated with positive results.^1- 2 We also emphasize that we used quality evaluation in our analyses to help evaluate the overall weight of evidence for efficacy of these compounds. This critical component of meta-analytic methodology should not be viewed as an attempt to discredit individual trials or investigators, nor was this our intent.