To comprehensively analyse the life expectancy at birth of people with intellectual disability, including people with Down syndrome, to inform health equity and service planning.

Retrospective cohort study.

Residents of New South Wales (NSW), Australia, with intellectual disability from birth onwards between 1 January 2001 and 31 December 2018.

Our study sample comprised 100 089 individuals with intellectual disability in the dataset, spanning from birth onwards, between 1 January 2001 and 31 December 2018.

All cause mortality. Life expectancy was estimated using ordinary and abridged life table methods, based on age-specific population count, and compared with the general NSW population.

Life expectancy at birth of people with intellectual disability was 67 years, 16 years shorter than the NSW average. Males and females with intellectual disability had a similar life expectancy. Individuals with Down syndrome had a life expectancy of 54 years, significantly shorter than those without Down syndrome. The life expectancy gap for people with intellectual disability narrowed with increasing age.

People with intellectual disability in Australia experience a substantial life expectancy gap, with greater disparities for those with Down syndrome. These findings underscore the need for targeted health and social interventions to address systemic inequities and improve health outcomes across the lifespan.

(1) Examine the associations between imprisonment history and mortality among adults with neurodevelopmental disabilities and (2) examine the associations between receipt of disability services and post-release mortality among adults with neurodevelopmental disabilities released from prison.

Population-based data-linkage cohort study using historical administrative data.

New South Wales (NSW), Australia.

67 217 adults aged ≥18 years (59.1% male) with one or more neurodevelopmental disabilities in NSW, Australia, from July 2001 to June 2015.

The main outcome measure was all-cause mortality. In the full cohort, we used Cox regression to examine the associations between release from imprisonment and all-cause mortality. In a subcohort of those released from prison, we used Poisson regression to examine the associations between receipt of disability services and post-release all-cause mortality.

3.3% of participants (n=2214) were imprisoned and released at least once during follow-up. In all age groups

Among adults with neurodevelopmental disabilities, mortality was increased among those released from prison compared with their peers who had not been imprisoned, although this was largely explained by health-related factors, including mental illness, substance use and physical comorbidity. Comprehensive policy and service system responses are required to meet the health and safety needs of people with neurodevelopmental disabilities who have complex needs, including criminal legal system involvement, mental illness and substance use.