Screening Tools for Early Identification of Adults at High Risk of Type 2 Diabetes: A Scoping Review

Background/Objectives: Global estimates suggest that approximately 43% of individuals living with diabetes remain undiagnosed, underscoring the need for early identification of adults at high risk of type 2 diabetes mellitus (T2DM) to support timely preventive interventions. This scoping review aimed to map and summarize existing non-invasive screening tools for identifying adults at high risk of T2DM. Methods: PubMed (MEDLINE), Web of Science, ScienceDirect, and Scopus were searched in accordance with the PRISMA extension for Scoping Reviews (PRISMA-ScR). Studies published between 1995 and 2026 that described screening tools for adult populations were included. Results: A total of 58 studies describing screening tools were identified. The tools were developed and applied across diverse populations and ethnic groups. Most were questionnaire-based, easy to administer, and low cost. Commonly included variables comprised demographic characteristics, anthropometric measures, lifestyle factors, and clinical indicators associated with increased T2DM risk. Substantial heterogeneity was observed in tool structure and reported predictive components. Conclusions: This scoping review provides an overview of available screening tools for the early identification of adults at high risk of T2DM. The mapped evidence may inform future validation studies and support context-specific implementation in public health and clinical practice settings, including integration into digital platforms.