Ontarians more likely to survive 1 year after hospitalization: study

September 30, 2013

Ottawa — More people in Ontario are living longer after hospitalization than in 1994, with a 22% decrease in the risk of death after one year from admission, found an article in published today in CMAJ (Canadian Medical Association Journal).

The population-based study analyzed the hospital records of more than 2.5 million Ontario adults and examined the one-year survival after admission to hospital for all adults admitted to hospital in Ontario, in 1994, 1999, 2004 and 2009 by linking to vital statistics datasets. The paper found that, compared to 1994, patients admitted to hospital in 2009 were:
  • much sicker (had increased comorbidities)
  • older (with a median age of 58 years compared with 51), and
  • were more likely to arrive by ambulance (25% compared with 16%).
As a result of these changes, the unadjusted risk of death one year after hospitalization increased from 9.2% to 11.6%. However, after correcting for factors such as those listed above the story was much different.

"Independent of patient age, sex and comorbidity, admission urgency and service, and ambulance status, the one-year adjusted odds of death were 22% lower in 2009 than in 1994, which is a significant decrease," said author Dr. Carl van Walraven, a senior scientist at the Ottawa Hospital Research Institute and site director of ICES uOttawa.

Another layer to the story is that the risk of death in the general population also declined during the study period. For people under the age of 50, the annual risk of death, compared with the risk in 1994, declined 18%, 22% and 28% respectively in 1999, 2004 and 2009. Although previous studies have looked at survival rates for specific diseases, none has accounted for survival changes in the general population when measuring trends in patient survival rates.

The improved trends in one-year survival for hospitalized patients persisted after adjusting for improved survival in the general population and the important changes in patient characteristics. Compared with patients in 1994, those in 2009 were 19% less likely to die within a year after admission to hospital.

“When we combine this significant decrease in the risk of death with the fact that hospitalizations are so common, it is clear that there have been significant gains in life-years for Ontarians. Further research needs to be done on hospital admissions and mortality since the reasons for this improvement cannot be determined from this study,” says van Walraven.

Media contact
Jennifer Ganton
Communications and Public Relations, Ottawa Hospital Research Institute
613-798-5555 x 73325
613-614-5253 (cell)

Deborah Creatura
Communications, ICES
416-904-4547 (cell)

About the Ottawa Hospital Research Institute (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. OHRI includes more than 1,700 scientists, clinical investigators, graduate students, postdoctoral fellows and staff conducting research to improve the understanding, prevention, diagnosis and treatment of human disease. Research at OHRI is supported by The Ottawa Hospital Foundation.

About ICES
ICES is an independent, non-profit organization that uses population-based health information to produce knowledge on a broad range of health care issues. Our unbiased evidence provides measures of health system performance, a clearer understanding of the shifting health care 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.