LAUSR

Editor We read with great interest the paper by Scholten et al.1. The aim of this systematic review was to focus on shortand long-term functional outcomes after total pancreatectomy, and its impact on quality of life. Although the results of the review are valuable, there is a methodological issue about the study that we believe must be addressed by the authors. Inclusion and exclusion criteria need to be clarified in much more detail. To establish these criteria, each aspect of the research question must be defined clearly to clarify exactly what the authors wish to focus on. Depending on the subject, it is strongly recommended that the Population, Intervention, Comparison, Outcomes and Study design (PICOS) is used2,3. The Cochrane Handbook for Systematic Reviews of Interventions4 specifies using PICOS as a framework for developing a review question, thus ensuring that the relevant components of the question are well defined. PICOS is also focused primarily on treatment questions, although it can also be adapted to formulate prognostic or diagnostic research questions2. Despite the existence of other frameworks including sample, phenomenon of interest, design, evaluation, research type (SPIDER) and setting, perspective, intervention, comparison, evaluation (SPICE), PICOS is by far the most widely used framework for structuring clinical research questions and defining eligibility criteria in the literature search2. PICOS and selection of eligible studies form the cornerstone of systematic reviews that ensure homogeneity and reliability. Therefore, when carrying out systematic reviews, the PICOS framework should be taken seriously to retrieve all eligible studies and avoid