An opportunity has been missed to improve care for people with type 2 diabetes in Northern Ireland, an audit office report has said.
The report examines the prevention and care of Type 2 diabetes, a disease which affects almost 6% of the adult population in Northern Ireland.
Numbers diagnosed have increased by over 70% since 2004-05, and are projected to reach 100,000 by 2020.
Comptroller and auditor general Kieran Donnelly said he was disappointed by limited implementation of a 2003 review pointing the way towards best practice.
He described a failure to introduce a comprehensive strategy until late 2016 as a "missed opportunity" to slow the growing prevalence of the disease, and to reduce the numbers of serious complications which can arise, including blindness and lower limb amputations.
Mr Donnelly added: "Type 2 diabetes is a matter of concern, both in terms of its impact on human life and its cost to the public purse."
"Already it is estimated that treating diabetes costs Northern Ireland £400m annually. This is 10% of the local healthcare budget and forecasts indicate this may rise to 17% of health spending by 2035."
He further stated: "The projected growth of Type 2 diabetes creates a real risk that the current model of care provision will become unsustainable.
"I can only conclude that, to date, value for money has not been achieved in delivering Type 2 diabetes services."
The report concluded that the Department of Health faces challenges in securing the necessary funding and effectively addressing areas of greatest priority.