TO THE EDITOR
I read with interest the article by Fernández-Hidalgo et al, comparing the effectiveness of the ampicillin plus ceftriaxone (AC) and ampicillin plus gentamicin (AG) combinations for treating Enterococcus faecalis infective endocarditis (EFIE) [1].
Although I recognize the clinical usefulness of this effort, in a field with limited therapeutic alternatives, I believe that the current evidence regarding AC versus AG treatment for EFIE does not support the conclusion that AC is as effective as AG in terms of mortality. I should note that this study had a superiority design, but aimed to claim for noninferiority—an inadequate approach [2–4]. A more comprehensive interpretation of the results would require a careful evaluation of the confidence intervals regarding the difference in mortality, not only the point estimates. This is of greater relevance given the relative small sample and limited statistical power. From the published data in the article’s Table 3, we can obtain the information shown in Table 1.
