The scheme (see box) was created by the RCGP and NHS Diabetes and seeks to untangle what the RCGP called an 'often complex diagnostic challenge'.
It follows an audit of one million patient records showing that around 40% of diabetes patients had classification anomalies in their data, risking confusion in care and hampering service planning.
For an average-sized practice, around 23 people will need reclassifying or rediagnosing at annual reviews.
An audit tool to allow practices to determine which patients' classification may need to be changed has been developed by researchers involved with the project. It is available from www.clininf.eu/cod. The tool can extract data from all the main practice IT system suppliers.
In a trial of the tool, around 40 patients were found in each of the five practices auditing the tool. For most of these patients, records could be assessed and amended relatively quickly, with the classification of only a few patients requiring more thorough analysis.