2210-P: Prototype Tool to Estimate the Probability of Type 1 Diabetes in Adults with New-Onset Diabetes across Four World Regions

Introduction and Objective: Type 1 diabetes in adults is frequently misclassified as type 2, delaying appropriate insulin treatment and leading to worse outcomes. We developed a probability-based tool that combines pre-laboratory clinical characteristics and laboratory results to estimate the likelihood of type 1 vs. type 2 diabetes among adults with new-onset diabetes across four geographic regions. Methods: We convened an expert panel to design a web-based tool using demographic, anthropometric, and laboratory data. We used the published University of Exeter type 1/type 2 diabetes clinical features model for Western Europe and estimated analogous region-specific logistic regression models for Northern Europe (Scania ANDIS), Eastern Europe (Ukraine Exomes), and South Asia (Mohan Clinics). Pre-laboratory type 1 diabetes probability was modelled using log(age at onset), log(BMI), male sex, and parental history. Likelihood ratios for islet autoantibodies (glutamic acid decarboxylase autoantibodies, insulinoma-associated protein-2 autoantibodies, zinc transporter 8 autoantibodies, insulin autoantibodies) were derived from a systematic review and regional datasets. Fasting C-peptide measured at or near diagnosis was modelled with gamma distributions for type 1 and type 2 diabetes to provide continuous likelihood ratios. Results: Across 139,518 adults with new-onset diabetes, the proportion with type 1 diabetes ranged from 2.8% in South Asia to 13.2% in Western Europe. We implemented demographic, anthropometric, and laboratory data in a prototype web-based calculator that generates a pre-laboratory probability and subsequently updates it with autoantibody and C-peptide results. Conclusion: This is the first region-adapted calculator for estimating the probability of type 1 vs. type 2 diabetes in adults with new-onset diabetes. With continued validation in new datasets, this tool has the potential to improve diagnostic accuracy in diabetes and enable earlier appropriate treatment for adults with new-onset diabetes. Disclosure L.K. Billings: Advisory Panel; Current; Novo Nordisk, Lilly, Sanofi, Amgen Inc., Bayer AG. S. Misra: Other - Speaker honorarium for a single presentation at a conferences; Ended; A. Menarini Diagnostics, Lilly Diabetes. Advisory Panel; Ended; Insulet Corporation. Other - Speaker honoararium for a single presentation at a conferences; Ended; Sanofi. M.A. Kohn: None. O. Asplund: None. E. Ahlqvist: Research Support; Current; AstraZeneca. Other - Honorarium for lecture; Ended; AstraZeneca. V. Mohan: None. T.K. Oleksyk: None. M.E. Al-Sofiani: Speaker's Bureau; Ended; Medtronic, Dexcom, Inc. Research Support; Current; Dexcom, Inc. Research Support; Ended; Medtronic. Speaker's Bureau; Ended; Insulet Corporation, Abbott Diabetes, Sanofi. J.M. Brix: Advisory Panel; Current; Abbott Diabetes, Boehringer Ingelheim International GmbH. Speaker's Bureau; Current; AstraZeneca. Speaker's Bureau; Ended; Dexcom, Inc. Speaker's Bureau; Current; Bayer AG. Advisory Panel; Current; Eli Lilly and Company, Merck Sharp & Dohme Corp. Speaker's Bureau; Ended; Medtronic. Advisory Panel; Current; Novo Nordisk. L. DiMeglio: Research Support; Ended; Dompé, Lilly. Stock/Shareholder; Ended; Lilly. Research Support; Current; MannKind Corporation. Research Support; Ended; Provention Bio, Inc. Research Support; Current; Sanofi. Research Support; Ended; Zealand Pharma A/S. Consultant; Current; Tandem Diabetes Care, Inc. Other - DSMB member; Current; Merck & Co., Inc., Lilly. K.L. Fantasia: Stock/Shareholder; Current; Eli Lilly and Company. D. Kerr: Stock/Shareholder; Current; Glooko, Inc. Research Support; Current; Abbott Diabetes. R. Ma: Research Support; Current; AstraZeneca. Speaker's Bureau; Ended; AstraZeneca. Research Support; Current; Boehringer Ingelheim International GmbH. Advisory Panel; Ended; Boehringer Ingelheim International GmbH. Research Support; Ended; Roche Diagnostics. Speaker's Bureau; Current; Roche Diagnostics. Speaker's Bureau; Ended; Eli Lilly and Company. Research Support; Ended; Novo Nordisk. Stock/Shareholder; Current; GemVCare Ltd. J.K. Mader: Research Support; Current; A. Menarini Diagnostics. Advisory Panel; Current; Abbott Diabetes. Speaker's Bureau; Current; Abbott Diabetes. Advisory Panel; Current; Becton, Dickinson and Company. Speaker's Bureau; Current; Becton, Dickinson and Company. Advisory Panel; Current; Insulet Corporation, Eli Lilly and Company. Speaker's Bureau; Current; Eli Lilly and Company. Advisory Panel; Current; Sanofi. Speaker's Bureau; Current; Sanofi. Advisory Panel; Current; Novo Nordisk A/S. Speaker's Bureau; Current; Novo Nordisk A/S. Advisory Panel; Current; Roche Diagnostics. Speaker's Bureau; Current; Roche Diagnostics. Advisory Panel; Current; Medtronic, Tandem Diabetes Care, Inc., Omnipod. Stock/Shareholder; Current; decide Clinical Software GmbH. Advisory Panel; Current; Dexcom, Inc. Speaker's Bureau; Current; Dexcom, Inc., Sinocare, Buzud. Advisory Panel; Current; Biomea Fusion, Pharmasens. Stock/Shareholder; Current; elyte Diagnostics. Other - CMO (unpaid); Current; elyte Diagnostics. Speaker's Bureau; Current; A. Menarini Diagnostics. Board Member; Current; OMNIA by AI APS. Advisory Panel; Current; Triple Jump. N. Mathioudakis: None. C. Mathieu: Advisory Panel; Current; Abbott Diagnostics, Dexcom, Inc. Board Member; Current; European Association for the Study of Diabetes. Advisory Panel; Current; Novo Nordisk, Eli Lilly and Company, Sanofi, Vertex Pharmaceuticals Incorporated, Medtronic. C. Mendez: None. Z. Quandt: Advisory Panel; Ended; Sanofi. M.J. Redondo: Advisory Panel; Current; Sanofi. Other - Data Safety Monitoring committee; Current; Lilly. E.D. Schleicher: None. V. Shah: Advisory Panel; Current; Abbott Diabetes, Dexcom, Inc. Advisory Panel; Ended; Medtronic. Advisory Panel; Current; Novo Nordisk, Eli Lilly and Company. Consultant; Current; Insulet Corporation, T1D Exchange. Advisory Panel; Current; Sanofi, Tandem Diabetes Care, Inc. Consultant; Ended; DreaMed Diabetes, Ltd. N. Thomas: Advisory Panel; Current; Sanofi. Other - Travel support; Ended; Sanofi. G. Umpierrez: Research Support; Current; Abbott, Dexcom, Inc., Bayer AG. Advisory Panel; Ended; Sanofi-Aventis U.S., Dexcom, Inc. Other - Education grant; Current; Lilly Diabetes, Abbott Diabetes. Advisory Panel; Current; Glycare, Glucotrack. Research Support; Current; Corcept Therapeutics. W. Wolfsberger: None. M. Shao: None. A.F. Scheideman: None. A.M. Zhou: None. A. Ayers: Consultant; Ended; Liom Health AG. D. Klonoff: Advisory Panel; Current; Afon Technology, Atropos Health, Embecta, Glooko, Inc., Glucotrack, Lifecare, Inc. Advisory Panel; Ended; Novo Nordisk. Advisory Panel; Current; Sanofi, Synchneuro, Thirdwayv Inc.