Population based diabetes registers have generated data on glycaemic control and clinical outcomes of young people with diabetes and enabled benchmarking across diabetes centres internationally. These registers demonstrate that many young people with type 1 diabetes have suboptimal glycaemic control, with most not reaching the internationally established HbA1c target for young people of <58mmol/mol (<7.5%). The Australasian Diabetes Data Network (ADDN), an initiative of APEG, ADS and the JDRFCRN, is a prospective longitudinal diabetes register that provides the first opportunity for long-term monitoring of diabetes outcomes in a national sample (1). The ADDN model involves transfer of de-identified prospectively collected patient data, using a common data dictionary, from the clinical database or electronic medical record system of participating ADDN centres. The data are transferred to a web-based staging server hosted by the University of Melbourne. The first phase of ADDN received data from the five largest Australian paediatric diabetes centres located in Adelaide, Brisbane, Melbourne, Perth and Sydney. At the end of 2015, data from centres represented 5,271 patients and 83,506 diabetes visits. The first analysis (2015 calendar year) demonstrated that only 27% of young people aged