In Reply:-We, as a research team, are concerned about the issues raised by Drs. Goto and Uezono and appreciate the opportunity to consider them openly. Clearly, we can only comment on the larger, FDA- monitored multicenter study published in Anesthesiology. 
Simply put, our study was a comparison between the COPA and LMA and not between sites. The valid comparison designed in the study is therefore between devices at each site and summarized in Table 7of the article. For instance, we compare the LMA versus COPA regarding the occurrence of any adverse event (81% vs. 61% at The Johns Hopkins Medical Institutions, 48% vs. 30% at Cairns Base Hospital, and 42% vs. 39% at Nambour General Hospital). Looking at these comparisons, one must recognize that the COPA did at least as well as the LMA. However, one might consider why events were more frequently reported at The Johns Hopkins Medical Institutions for both devices (either because of more overall problems or perhaps superior recognition and recording). In fact, based on this analysis, the Australian sites did not have more difficulty with the COPA compared with the LMA; in only two instances were the percentage of adverse events higher with the COPA.
We have made every effort to perform and report our research in the most unbiased way possible. Because we did not participate in the study reported in Anesthesia & Analgesia, we are unable to comment on the actual design or conduct of their study or effort to control for personal bias, etc. We are therefore unable to comment on the differences in conclusions between the two papers.
Robert S. Greenberg, M.D.
Victoria Gouze, M.D.
Steven Piantadosi, M.D., Ph.D.
Elizabeth M. Dake, M.S.
The Johns Hopkins Medical Institutions; Baltimore, Maryland
(Accepted for publication December 14, 1998.)