New Ottawa decision tool identifies high-risk lung patients

Posted on Tuesday, February 18, 2014

A new decision tool developed in Ottawa will help emergency physicians everywhere identify patients with chronic obstructive pulmonary disease (COPD) who are at risk of serious complications or death. The Ottawa COPD Risk Scale was published today in the Canadian Medical Association Journal.

“We expect this risk scale, once fully validated, to be used widely in emergency departments to improve patient safety, by identifying those who need to be admitted to hospital and those who could safely be sent home,” says Dr. Ian Stiell, chair of the University of Ottawa Department of Emergency Medicine, University health research chair, emergency physician at the Ottawa Hospital and senior scientist at the Ottawa Hospital Research Institute. Stiell is world renowned for creating highly useful decision rules, such as the Ottawa Ankle Rules and the Canadian C-Spine Rule.

Chronic obstructive pulmonary disease, usually caused by smoking, is a leading cause of hospitalization for seniors. Moreover, over one-third of people hospitalized for COPD end up at an emergency department within 30 days of discharge.

It can be challenging for emergency physicians to determine which COPD patients should be admitted because, until now, there has been little evidence to guide them concerning the risk factors for adverse events in patients with this condition. Adverse events include death within 30 days of visiting an emergency department, intubation or ventilation, heart attack and other serious occurrences.

Researchers looked at data from 945 patients aged 50 years or older in six Canadian teaching hospitals (in Ottawa, Toronto, Kingston, Montreal, Quebec City and Edmonton) to determine characteristics associated with short-term adverse events. After analyzing 20 clinical and laboratory predictors of risk, they developed the Ottawa COPD Risk Scale, a 10-point scale that includes elements from a patient's history, examination and tests conducted during his or her visit.

The risk factors are easy to determine without expensive testing.  The tool provides physicians with a quantitative estimate of risk for adverse events in COPD patients.

“We found that the risk of a serious adverse event varied from 2.2%, for a score of 0, to 91.4%, for a total score of 10,” says Stiell.

The researchers also found that 62% of COPD patients were being sent home from emergency departments in Canada, compared to 20% in the United States. They suggest that this is partly due to bed shortages and the resulting pressure on physicians to be sure that hospitalization is necessary.

“We are concerned by the number of serious adverse events among COPD patients discharged from the emergency department,” write Stiell and his co-authors. “Identification of high-risk characteristics by physicians has the potential to significantly improve patient safety by helping to ensure that patients most at risk for poor outcomes be admitted.”

They suggest the tool could also be used to identify patients who should have early follow-up for COPD after discharge from hospital.

The tool was developed by researchers at the Ottawa Hospital Research Institute, the University of Ottawa Heart Institute, the University of Ottawa, the University of Toronto, Queen's University, the University of Calgary and the University of Alberta.

The study, “Clinical characteristics associated with increased risk of adverse events in patients presenting to the emergency department with exacerbation of chronic obstructive pulmonary disease: a prospective cohort study,” was authored by Ian G. Stiell, Catherine M Clement, Shawn D. Aaron, Brian H. Rowe, Jeffrey J. Perry, Robert J. Brison, Lisa A. Calder, Eddy Lang, Bjug Borgundvaag, Alan J. Forster and George A. Wells.  

It was funded by the Canadian Institutes of Health Research, the University of Ottawa (University Health Research Chair and Clinical Research Chair), the Government of Canada (Canada Research Chair) and the Ottawa Hospital Foundation.

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