The UNITED study was a population-based study looking at individuals aged below 50 years, diagnosed with diabetes before the age of 30 years. Typically, such individuals will be diagnosed with Type 1 (T1DM) but a number of these individuals will in fact have a form of monogenic diabetes. Often, these subsets of diabetes respond better to treatments other than insulin, or no treatment at all. UNITED participants underwent a 3 step algorithm with progression to the next step being determined by their results. All participants had an initial UCPCR test, unless their diabetes treatment was diet only (and therefore producing insulin), to measure endogenous insulin. Participants that were UCPCR positive and producing insulin were tested for pancreatic autoantibodies to determine the likelihood of having type 1 diabetes. The final stage of the UNITED pathway was for those with negative autoantibodies and endogenous insulin production to undergo a genetic test for monogenic diabetes. If found to have monogenic diabetes, their diabetes treatment was reviewed and changed as appropriate. The majority of participants had T1DM: of 1875, 131 were found to have T2DM and 60 were found to have some form of MODY.