Dr Palmowski-Wolfe asks how clinical trial registration will improve ethics if there is no way to enforce publication of all trial results, both positive and negative. Yes, publication, or at least dissemination, of all trial results is a better method for making sure that the results of studies are not hidden. But even if a trial is never published, it can still be discovered if it is registered, and in this way the unpublished findings can be uncovered.
Levin LA. Regarding Registration of Clinical Trials—Reply. Arch Ophthalmol. 2007;125(6):853. doi:10.1001/archopht.125.6.853-b