Evaluation of guidelines on diabetes medication

we read the review by Bennett WL et al with interest. Unfortunately, the Authors restricted their research to the U.S., U.K., and Canadian databases because they "deemed these countries' guideline developers most likely to access and use the systematic review". The Italian Standards for the Treatment of Diabetes Mellitus represent a consensus document of the two Italian scientific diabetes societies (AMD and SID), providing specific recommendations for the diagnosis and treatment of diabetes and its complications. An original processing system was employed: the document prepared by the Editorial Team was published online for 20 days, and the suggestions and criticisms of all the Scientific Society members were evaluated and integrated with those provided by a panel of diabetologists and members of other healthcare professions committed to diabetes care, as well as lay members, including patients' representatives. These guidelines include recommendations on oral medications for Type 2 Diabetes Mellitus. In our opinion, the recommendation presented in the Italian Standards of Care fully fulfil the 7-item rigor of development domain of the Appraisal of Guidelines Research and Evaluation (AGREE) instrument (3) and we believe that, if taken into appropriate consideration, they would probably earn the best appraisal score in the Bennett WL et al re-evaluation. As all the examined guidelines, Italian Standards of Care propose metformin as first-line agent (upon and beyond lifestyle education) and acknowledge that most medications cause similar reductions in HbA1c, suggesting an accurate and personalized prescription behaviour based on wellknown and demonstrated side effects, rather than intriguing, but still hypothetical, pathophysiologic choices. We would also like to specifically comment on the series of ADA/EASD documents; these algorithms are based on the personal opinion of experts, and generate consensus statements that are far from a guideline based on published evidence. This observation, for example, explains why the various versions of these consensuses substantially changed important medication choices over time, and is also the main reason that probably excluded their inclusion in the ADA Standards of Care. We are, therefore, glad that Bennett and co-workers indirectly appreciated our work in establishing Italian guidelines for the oral management of type 2 diabetes, and hope that a rigorous distinction between evidence-based guidelines and expert opinions will become more tangible.