All-cause and cause-specific mortality inequalities between people with and without disability: a nationwide data linkage study in Australia

Background: Without high-quality statistics on mortality inequalities, designing policies to improve the health of people with disability is challenging. We aim to quantify mortality inequalities experienced by people with disability in Australia.

Methods: In this nationwide, data linkage study we used Census mortality linked data (2011-20) to construct a cohort of Australians aged 0-74 years. Disability was measured as requiring assistance or supervision in core daily activities. We estimated age-standardised and age-specific mortality rates, and absolute and relative mortality inequalities between people with and without disability.

Findings: 15 216 195 people were included in the study, comprising 7 763 047 females and 7 453 148 males. Of the participants, 258 109 (3·5%) males and 228 658 (2·9%) females reported disability, with 462 990 deaths occurring over 138 540 359 person-years of follow-up. Per 100 000 person-years, there were 2067 (95% CI 2043-2091) more deaths in males and 1697 (1677-1718) more deaths in females with disability (3·69 and 4·64 times higher, respectively) than those without disability. Cancer and cardiovascular disease had the highest absolute inequalities, with rate differences of 462 (95% CI 449-476) for males and 368 (356-379) for females for cancer, and 471 (95% CI 459-483) for males and 333 (324-342) for females for cardiovascular disease. Less common causes among people without disability-neurological conditions, chronic lung diseases, endocrine diseases, and digestive diseases-are relatively common among people with disability, translating to high relative mortality inequalities. The largest relative inequalities were from neurological conditions, with rate ratios of 9·66 (95% CI 9·31-10·02) for males and 11·61 (11·13-12·10) for females. Relative and absolute inequalities were also substantial for unintentional injury and for suicide mortality. Age-specific mortality was consistently higher in people with disability. The leading contributors to absolute inequalities shifted from neurological conditions in younger ages to cancer, cardiovascular diseases, and chronic lung diseases in older ages.

Interpretation: People with disability experience large mortality inequalities. Identifying intervention-amenable factors contributing to these inequalities should be a priority. Targeted interventions and policy reforms to create a more inclusive social and health-care environment for people with disability might be necessary.

Funding: The University of Melbourne.