(144) Trends of the prevalence of polypharmacy and potentially inappropriate medications in people with dementia from 2006 to 2021 in Hong Kong

Background:
Long-term prescription patterns of polypharmacy and potentially inappropriate medication (PIMs) in people with dementia were limitedly studied in Chinese population.

Objective:
Analyze the prevalence trends of polypharmacy, hyperpolypharmacy and PIMs in people living with dementia.

Methods:
Electronic healthcare data from Hong Kong (2006-2021) was used to evaluate the trends of polypharmacy (≥5 medications) and hyperpolypharmacy (≥10 medications) prescribed for more than 60 days per year in dementia patients aged 65 years or older. PIMs were identified according to the 2019 Beers criteria and the Screening Tool of Older Person's Prescription version 2, with at least one prescription per year. The pandemic period was defined as 2020-2021. The prevalence of polypharmacy, hyperpolypharmacy, and PIMs was calculated as dividing the affected people by the total number of people with dementia alive each year. Joinpoint regression models analyzed trends and estimated their average annual percent change (AAPC).

Results:
The prevalence of polypharmacy increased from 2006 (36.4%) to 2021 (66.4%) (AAPC: 4.0). Hyperpolypharmacy also increased from 3.3% to 21.0% (AAPC:12.7). During the pandemic, stable trends were observed in polypharmacy (p=0.08) and hyperpolypharmacy (p=0.20). The prevalence trend of PIMs from 2006 to 2021 was stable (35.8%-35.2%, p=0.17), with a slight increase observed from 2015 onward (33.5%-35.2%, p<0.001). Between 2006 and 2013, and after the release of the new guideline (2019 to 2021), the prescription of antipsychotics and anticholinergics decreased (both p-values <0.001), while prescriptions for non-benzodiazepine (AAPC: 4.4) and benzodiazepine (AAPC: 3.6) increased.

Conclusions:
Trends of polypharmacy and hyperpolypharmacy increased among people with dementia. The prescription of PIMs is stable, with an increase from 2015 to 2021. Reviewing polypharmacy and hyperpolypharmacy among people living with dementia is needed to ensure the appropriate use of medications.