People with schizophrenia are three times more likely to die, and die younger, than the general population, indicating a need for solutions to narrow this gap, according to research published in CMAJ (Canadian Medical Association Journal).
This large study looked at all deaths in Ontario over a 20-year period (1993-2012) -- more than 1.6 million deaths -- to understand trends in schizophrenia. Of these, 31 349 were deaths of people with schizophrenia and more were female, younger and living in lower-income neighbourhoods compared with the general population. Despite increases in life expectancy, people with schizophrenia died 8 years younger than the general population (age at death increased from an average of 64.7 to 67.4 years of age from 1993 to 2012 among people with schizophrenia compared with 73.3 to 76.7 years in general population). Death from all causes decreased 35% in parallel in both groups.
Previous studies identified people with schizophrenia using hospital admissions, which biases towards more severe illness or use a severe mental illness category that includes illnesses other than schizophrenia. In Ontario, researchers have developed methods and have access to data that allow for more comprehensive and more accurate analysis about the relation between schizophrenia and mortality.
High death rates among people with schizophrenia have also been shown in previous small studies and those from other countries such as Scandinavia and Australia.
"It's clear that there is not enough evidence to support what we should be doing," says Dr. Paul Kurdyak, Centre for Addiction and Mental Health and the Institute for Clinical Evaluative Sciences, Toronto, Ontario. "This study, in addition to documenting astonishingly high mortality rates, also points to an equity issue -- that individuals with schizophrenia are not benefiting from public health and health care interventions to the same degree as individuals without schizophrenia. The complex needs of individuals with schizophrenia and comorbid medical conditions create a tremendous challenge to providers and health care systems more broadly." Dr. Kurdyak is also Director of Health Outcomes with the Medical Psychiatry Alliance.
People with schizophrenia have not benefited from reductions in cardiovascular deaths seen in the general population. Access to health care and lifestyle, such as higher rates of smoking, alcohol consumption, poor diets and lack of exercise may explain the higher mortality risk for people with schizophrenia.
"Although there have been numerous calls to action to help individuals with severe mental illness, such as schizophrenia, to manage chronic medical illnesses, and although the declining trends and narrowing absolute gap that we observed are positive developments, more effort is required to reduce the considerable disparity in both mortality and illness burden," the study concludes.
"A gap in life expectancy of this size for any other group of patients might reasonably be expected to lead to correspondingly substantial public health action to redress the health inequality," writes Dr. Philip Ward, University of New South Wales Sydney, Sydney, Australia, in a related commentary. "However, this does not appear to be the case for people with schizophrenia."
He suggests that strategies to reduce smoking, diet and exercise interventions to counteract weight gain experienced from drugs to control schizophrenia and managing chronic disease can help narrow the life expectancy gap.
The research study was funded by the Institute for Clinical Evaluative Sciences (ICES), the Ontario Ministry of Health and Long-term Care, and the Medical Psychiatry Alliance.
"Trends in standardized mortality among individuals with schizophrenia, 1993-2012: a population-based, repeated cross-sectional study" and related commentary are published September 18, 2017.
Podcast public link: https://soundcloud.com/cmajpodcasts/161351-res
Visual abstract public link: http://www.cmaj.ca/lookup/suppl/doi:10.1503/cmaj.161351/-/DC2
Canadian Medical Association Journal