Cause of death in adults with intellectual disability in the United States

Prior studies report that adults with intellectual disability (ID) have cause of death patterns distinct from adults in the general population but do not provide comparative analysis by specific causes of death.

Data are from the National Vital Statistics System 2005-2017 US Multiple Cause-of-Death Mortality files. We utilised adjusted odds ratios to identify causes of death that were more common for adults whose death certificate indicated ID (N = 22 512) than for adults whose death certificate did not indicate ID (N = 32 738 229), controlling for severity level of ID. We then examine the associations between biological sex and race-ethnicity and causes of death solely among adults with ID.

The leading cause of death for adults with and without ID indicated on their death certificate was heart disease. Adults with ID, regardless of the severity of the disability, had substantially higher risk of death from pneumonitis, influenza/pneumonia and choking. Adults with mild/moderate ID also had higher risk of death from diabetes mellitus. Differences in cause of death trends were associated with biological sex and race-ethnicity.

Efforts to reduce premature mortality for adults with ID should attend to risk factors for causes of death typical in the general population such as heart disease and cancer, but also should be cognisant of increased risk of death from choking among all adults with ID, and diabetes among adults with mild/moderate ID. Further research is needed to better understand the factors determining comparatively lower rates of death from neoplasms and demographic differences in causes of death among adults with ID.