Dementia and intentional and unintentional poisoning in older people: a 10 year review of hospitalization records in New South Wales, Australia.

BACKGROUND

Medicinal substances have been identified as common agents of both unintentional and intentional poisoning among older people, including those with dementia. This study aims to compare the characteristics of poisoning resulting in hospitalization in older people with and without dementia and their clinical outcomes.

METHODS

A retrospective cohort study involving an examination of poisoning by intent involving individuals aged 50+ years with and without dementia using linked hospitalization and mortality records during 2003-2012. Individuals who had dementia were identified from hospital diagnoses and unintentional and intentional poisoning was identified using external cause classifications. The epidemiological profile (i.e. individual and incident characteristics) of poisoning by intent and dementia status was compared, along with clinical outcomes of hospital length of stay (LOS), 28-day readmission and 30-day mortality.

RESULTS

The hospitalization rate for unintentional and intentional poisoning for individuals with dementia was double and 1.5 times higher than the rates for individuals without dementia (69.5 and 31.6 per 100,000) and (56.4 and 32.5 per 100,000). [corrected]. The home was the most common location of poisoning. Unintentional poisoning was more likely to involve individuals residing in aged care facilities (OR 2.12; 95%CI 1.70-2.63) or health service facilities (OR 4.56; 95%CI 4.06-5.13). [corrected]. There were higher mortality rates and longer length of stay [corrected] for unintentional poisoning for individuals with dementia.

CONCLUSIONS

Clinicians need to be aware of the risks of poisoning for individuals with dementia and care is required in appropriate prescription, safe administration, and potential for self-harm with commonly used medications, such as anticholinesterase medications, antihypertensive drugs, and laxatives.