Abstract
Importance People with mental illness have a reduced life expectancy, but the extent of the mortality gap and the contribution of natural and unnatural causes to excess mortality among people with mental illness in South Africa are unknown.
Objective To quantify excess mortality due to natural and unnatural causes associated with mental illness.
Design, setting and participants Cohort study using reimbursement claims and vital registration of beneficiaries of a South African medical insurance scheme, aged 15-84 years and covered by medical insurance at any point between January 1, 2011, and June 30, 2020.
Exposures ICD-10 diagnoses of mental disorders including organic, substance use, psychotic, mood, anxiety, eating, personality, and developmental disorders.
Outcomes Mortality from natural, unnatural, unknown and all causes, as measured by the life-years lost (LYL) metric.
Results We followed 1 070 183 beneficiaries (51.7% female, median age 36.1 years for a median duration of 3.0 years, of whom 282 926 (26.4%) received mental health diagnoses and 27 640 (2.6%) died. Life expectancy of people with mental health diagnoses was 3.83 years (95% CI 3.58-4.10) shorter for men and 2.19 years (1.97-2.41) shorter for women. Excess mortality varied by sex and diagnosis, ranging from 11.50 LYL (95% CI 9.79-13.07) among men with alcohol use disorder to 0.87 LYL (0.40-1.43) among women with generalised anxiety disorder. Most LYL were attributable to natural causes (3.42 among men and 1.94 among women). A considerable number of LYL were attributable to unnatural causes among men with bipolar (1.52) or substance use (2.45) disorder.
Conclusions and Relevance The burden of premature mortality among persons with mental disorders in South Africa is high. Our findings support implementing interventions for prevention, early detection, and treatment of physical comorbidities among people with mental disorders. Suicide prevention and substance use treatment programmes are needed to reduce excess mortality from unnatural causes, especially among men.
Question How much shorter is the life expectancy of people with mental illness compared to the general population and how many life years are lost due to natural and unnatural causes of death?
Findings The life expectancy of people with mental health diagnoses was 3.83 years shorter for men and 2.19 years shorter for women. Most excess life years lost were attributable to natural causes (3.42 among men and 1.94 among women). However, bipolar and substance use disorders were associated with considerable premature mortality from unnatural causes.
Meaning Our findings support the implementation of interventions for improving the physical health of people with mental illness and targeted suicide prevention and substance use treatment programmes.
Competing Interest Statement
The authors have declared no competing interest.
Funding Statement
Research reported in this publication was supported by the Swiss National Science Foundation (grant numbers 193381, and 189498) and the US National Institutes of Health (the National Institute of Allergy and Infectious Diseases, the Eunice Kennedy Shriver National Institute of Child Health and Human Development, the National Cancer Institute, the National Institute of Mental Health, the National Institute on Drug Abuse, the National Heart, Lung, and Blood Institute, the National Institute on Alcohol Abuse and Alcoholism, the National Institute of Diabetes and Digestive and Kidney Diseases, and the Fogarty International Center) (grant number U01AI069924).
Author Declarations
I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.
Yes
The details of the IRB/oversight body that provided approval or exemption for the research described are given below:
The Human Research Ethics Committee of the University of Cape Town and the Cantonal Ethics Committee of the Canton of Bern granted permission to analyse these data.
I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.
Yes
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Footnotes
↵* Joint first authors
Minor revisions
Data Availability
Data were obtained from the International epidemiology Databases to Evaluate AIDS-Southern Africa (IeDEA-SA). Data cannot be made available online because of legal and ethical restrictions. To request data, readers may contact IeDEA-SA for consideration by filling out the online form available at https://www.iedea-sa.org/contact-us/. Statistical code is available under https://github.com/IeDEA-SA/LYL