After pioneering examples, such as the Lothian surgical audit scheme,1 the benefits of extending audit beyond a single hospital have increasingly been recognised.2 Few absolute standards exist in clinical care, and, unless clinicians compare their performance with that of a sufficiently large number of others, opportunities for improvement may be missed. Also, increasing specialisation often makes it necessary to look beyond the boundaries of a single hospital to compare results with others.

In theory, large datasets could help in this process by highlighting unsuspected variations in care or by identifying events that should not normally occur.3 This requires the datasets to be accurate, meaningful, and accessible. Many clinicians have concluded that, despite a massive investment in technology, routinely collected data still fail to meet these criteria and that separate systems are required. Does the evidence support this? Do specially designed information systems yield more accurate data? Even if they do, are they sufficiently accurate to support audit?

Two recent papers from the same team …