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Simple tool identifies patients who may need closer monitoring after leaving hospital


Canadian researchers have developed a simple tool to predict the probability that a patient discharged from hospital to the community will die or be unexpectedly readmitted within 30 days. The study, published in the Canadian Medical Association Journal, could help identify patients who may benefit from closer monitoring and care, so that serious health problems can be prevented.

The tool was developed by a group of Canadian researchers led by Dr. Carl van Walraven of the Ottawa Hospital Research Institute (OHRI), the University of Ottawa and the Institute for Clinical Evaluative Sciences (ICES). The group examined detailed medical records from 4,812 people discharged from 11 Ontario hospitals between 2002 and 2006 and found that four factors could predict the risk of death or readmission. They called the tool LACE to coincide with the factors, which are:

  • Length of stay in hospital
  • Acuity of the admission (whether or not it was through the emergency department)
  • Comorbidity of the patient (a score based on what chronic diseases the patient has)
  • Emergency room utilization (number of visits in the previous six months)

Each factor is assigned a number of points based on its value. When these points are added together (as indicated on page 3 of the paper), they form the total LACE score. People with a score of zero had only a 2 per cent risk of death or readmission, while people with a score of 19 (the highest) had a 44 per cent risk. The researchers obtained similar results when testing the LACE tool using records from 1 million Ontario patients discharged between 2004 and 2008.

“Ontario hospitals provide exceptional care, but many patients still face serious health challenges in the weeks following a hospital discharge,” said Dr. van Walraven. “This research is an important step towards identifying those who are most at risk, so that hopefully we can address their health problems earlier and prevent serious complications.”

This study is part of a larger program that is using Ontario health records to find novel ways to improve health. OHRI, The Ottawa Hospital and the University of Ottawa will soon open a new ICES site to advance these efforts. The Ottawa Hospital Data Warehouse will also play a key role.

Dr. van Walraven is a senior scientist at OHRI, an internal medicine specialist at The Ottawa Hospital and a professor of medicine at the University of Ottawa. This study was funded by the Canadian Institutes of Health Research, the PSI Foundation and the University of Ottawa Department of Medicine.

  • About OHRI
  • The Ottawa Hospital Research Institute (OHRI) is the research arm of The Ottawa Hospital and is an affiliated institute of the University of Ottawa, closely associated with the University’s Faculties of Medicine and Health Sciences. The OHRI includes more than 1,500 scientists, clinical investigators, graduate students, postdoctoral fellows and staff conducting research to improve the understanding, prevention, diagnosis and treatment of human disease. www.ohri.ca
  • About ICES
  • ICES is an independent, non-profit organization that uses population-based health information to produce knowledge on a broad range of healthcare issues. Our unbiased evidence provides measures of health system performance, a clearer understanding of the shifting healthcare needs of Ontarians, and a stimulus for discussion of practical solutions to optimize scarce resources. ICES knowledge is highly regarded in Canada and abroad, and is widely used by government, hospitals, planners, and practitioners to make decisions about care delivery and to develop policy.
  • Jennifer Paterson
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  • Ottawa Hospital Research Institute
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  • Deborah Creatura
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