Capsule endoscopy in Italy: An unbalanced review of the literature. Authors' response

Abstract

The comments by Spada et al. (which are similar in style and content to the ones already made by the authors on the Italian Ministry of Health Web site) are based on misunderstandings and manipulations. The essence of systematic reviews is to sum up available knowledge and minimize bias. The latter is done by a priori stating study inclusion criteria both in the protocol and in the full HTA report (see Fig. 1, p. 299) and assessing methodological quality of included studies using an instrument which was specified in the protocol text and never changed (the Quality Assessment Diagnostic Accuracy Studies checklist or QUADAS). The purpose of inclusion criteria and bias minimization efforts is to ensure that what is included in a review is both relevant and contributes evidence weighted by its reliability to answer the study question (in our case the diagnostic performance of WCE in the small bowel). The high number of excluded studies is thus irrelevant, although it is a common feature of systematic reviews. What matters is what the included studies tell us.