The LACE index developed by the Canadian researchers is a new index to score patients being discharged from hospital on their risk of dying or being readmitted in the next 30 days.

A high score on the so-called LACE index, signals that the patient needs extra attention in the days to come.

"One of the things that one can do for a high-risk person is to follow them much more closely than you would otherwise", said Dr. Carl van Walraven of the Ottawa Hospital Research Institute.

Information was collected from almost 5,000 patients at 11 Ontario hospitals as they were leaving hospital, and were contacted after 30 days to see if there had been any urgent readmissions or deaths.

Of the 4,812 medical and surgical patients discharged, 8% died or were readmitted.

Henceforth from the observations, a mathematical model was evolved which allowed to access the probability of a bad outcome, with four key variables emerging, namely the length of stay in hospital, acuity of the original admission, comorbidities and emergency department use.

The data from the Institute for Clinical Evaluative Sciences was used to validate the LACE model in a million different patients in Ontario.