Poisoning among older people with dementia


The November International Psychogeriatrics Article of the Month is entitled “Dementia and intentional and unintentional poisoning in older people: a 10 year review of hospitalization records in New South Wales, Australia” by Rebecca J. Mitchell, Lara A. Harvey, Henry Brodaty, Brian Draper and Jacqueline C. T. Close.

This blog post was written for us by one of the paper’s authors, Rebecca Mitchell.

Older people who have dementia are hospitalized far more commonly than people without dementia. One of the most common reasons that older people with dementia are hospitalized is due to injuries, with poisoning one of the most common types of injury experienced. Some poisonings may be unintentional mistakes, but others are due to a person intentionally trying to harm themselves.

It is not surprising that older people with dementia might experience difficulty with taking different doses of medication on specific days or at specific times. In this study, we wished to identify if older people with dementia had a higher rate of being hospitalised following poisoning than people without dementia and to try to identify commonalities surrounding the circumstances of the poisoning event that would allow us to raise awareness of approaches needed to prevent future poisonings.

Most research that has looked at older people with dementia and poisoning has involved small studies that examined admission at only one or two hospitals. In this study, we were able to examine all hospital admissions following poisoning of older people in the largest state in Australia, New South Wales, and to identify the circumstances of the poisoning event for both people with and without dementia.

Our research found that older people with dementia had double the rate of hospitalisations for unintentional poisoning and one and a half times the rate of hospitalisation for intentional poisoning compared to older people who did not have dementia. We identified that anticholinesterase medications (taken for Alzheimer’s disease), antihypertensive drugs and laxatives were the common medications taken by an older person with dementia when they unintentionally poisoned themselves. The home was the most common location of the poisoning, but unintentional poisoning was 5 times more likely to occur in aged care facilities and at least 4 times more likely to occur in health service facilities compared to intentional poisoning.

As all people age, the number of medications they take generally increase, with around 4 or more medications taken by people aged 60 years and older. It is more common for mistakes with medications to be made, the higher the number of medications that need to be taken. The presence of dementia is only likely to increase the potential for errors to be made and make problems of adherence to a medication regimen more difficult.

The findings of our study suggest that there are opportunities to prevent unintentional poisoning by older people with dementia by improving medication storage options, such as the use of blister packs or Dosette boxes, by getting family members or carers to assist in medication administration and, in the aged care and hospital settings, by ensuring quality use of medicines, and accurate documentation and review regarding polypharmacy.

The full paper “Dementia and intentional and unintentional poisoning in older people: a 10 year review of hospitalization records in New South Wales, Australia” is available free of charge for a limited time here.

The commentary paper “Poisoning among older people with dementia: a wake up call” by Christopher D. Etherton-Beer is also available free of charge here.

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