# Inequalities in cancer mortality between people with and without disability: A nationwide data linkage study of 10 million adults in Australia

## TL;DR

People with disability in Australia have higher cancer mortality rates than those without disability, with lung, breast, and colorectal cancers being major contributors.

## Contribution

The study quantifies cancer mortality inequalities between people with and without disability using nationwide data, highlighting preventable cancers as key contributors.

## Key findings

- People with disability had significantly higher cancer mortality rates than those without disability.
- Lung cancer was the largest contributor to mortality inequalities in both males and females.
- Cancers linked to modifiable risk factors like smoking and obesity drive much of the mortality gap.

## Abstract

Cancer is a major yet under-recognised contributor to the mortality gap between people with and without disability. Our study aims to quantify these inequalities to inform cancer control efforts to reduce the gap.

We used nationally-linked data (2011–2022) to construct a cohort of over 10 million adults in Australia aged 25–74 years. Disability was measured in 2011 Census as requiring assistance in core daily activities and cancer related deaths identified in national death registrations. We estimated age-standardised and age-specific cancer mortality rates, and absolute and relative mortality inequalities (rate differences and ratios) between people with and without disability. The study included 10,414,951 people. Of the 5,403,503 females, 185,801 (3.4%) reported disability; 183,594 of the 5,011,448 males (3.7%) reported disability. Over 93,940,222 person-years (9.2 years on average), 219,257 cancer-related deaths occurred. After age-standardisation, per 100,000 person-years, there were 314 (95% confidence intervals [CI]: 301, 328) more cancer related deaths in females and 410 (95% CI: 394, 427) more in males with disability (1.96 [95% CI: 1.92, 2.00], and 1.83 [95% CI: 1.80, 1.87] times higher, respectively) than those without disability. The largest absolute inequalities were for lung cancer in both females and males (67 [95% CI: 60, 73] and 103 [95% CI: 95, 111] more deaths per 100,000 person-years, respectively), followed by breast cancer in females (54 [95% CI: 49, 60] more deaths), prostate cancer in males (31 [95% CI: 26, 36] more deaths), and colorectal cancer in both sexes (30 more [95% CI: 25, 34] deaths in females and 44 [95% CI: 38, 49] more in males). By 5-year age group, lung cancer was the leading contributor to absolute inequalities in females and males aged 35 years and older. In females, across most age groups, breast cancer was the second largest contributor to absolute inequalities, followed by colorectal cancer. In males, colorectal cancer was the second largest contributor across most age groups, with prostate cancer contributing substantially to absolute inequalities in those aged 55 years and older. A substantial proportion of differences in cancer-related deaths between people with and without disability, across most age groups in both females and males were driven by cancers linked to smoking, obesity, and alcohol consumption. We found similar-sized relative inequalities between individuals with and without disability in mortality due to individual cancers in both sexes. The main limitation of the study was that disability status was measured at a single time point.

People with disability had higher cancer mortality overall and in relation to specific cancers than people without disability. To close the gap, effort should prioritise interventions that work for people with disability across the cancer control pathway.

Deaths due to cancer are a major yet under-recognised public health concern for people with disability.

This study aimed to find out whether people with disability in Australia die from cancer more often than people without disability.

We used disability information collected in the Australian Census in 2011.

We obtained information on date of death and cause of death up to 2022 from death registrations.

We found higher death rate in people with disability compared with those without due to a range of cancers.

Much of this higher cancer-related death rate is linked to cancers that can be prevented or detected early through screening programs, and cancers associated with modifiable risk factors like smoking, obesity, and alcohol use.

These findings show that people with disability face inequalities in cancer outcomes that could potentially be avoided.

Further research is needed to understand the causes of these inequalities.

Together with past evidence, the findings highlight the importance of making cancer prevention, screening and care more accessible and tailored to the needs of people with disability

Addressing these inequalities could help reduce avoidable cancer-related deaths among people with disability.

The main limitation was that disability status was recorded only on the 2011 Census day, and we could not track any changes over time.

Yi Yang and colleagues estimate overall and type-specific cancer mortality inequalities between adults with and without disability in Australia, reporting both relative and absolute inequalities to inform cancer control efforts and research priorities.