Scientific societies such as the Infectious Disease Society of America (IDSA) and the Food and Drug Administration (FDA) consider the non-inferiority design for clinical trials of patients with VAP to be appropriate, using as the primary indicator the outcome of mortality at 30 days of follow-up, and using a non-inferiority absolute margin of 10%. The MagicBullet trial meets each of these criteria. Scientific societies also recommend that the effectiveness evaluation is performed in the population with microbiological diagnosis and per intention-totreat analysis. In the MagicBullet protocol, the efficacy evaluation was initially planned to be performed with
patients with clinical diagnosis (clinical and radiological) and who were part of the intention-to-treat population.This design has been used for the last antimicrobial approval, doripenem, for indication of VAP [27]. In order to use the same evaluation criteria for efficacy that has been proposed by the FDA and scientific societies, evaluation criteria for effectiveness were modified for efficacy assessment, considering microbiologically evaluable patients per intention to treat (patients with confirmed culture in respiratory sample and who had received at least one dose of experimental or control drug).