Potentially Inappropriate Prescribing in Long-Term Care and its Relationship With Probable Delirium.

OBJECTIVES

This study examined potentially inappropriate prescribing (PIP) of medication and its association with probable delirium among long-term care (LTC) residents in Ontario, Canada.

DESIGN

Population-based cross-sectional study using provincial health administrative data, including LTC assessment data via the Resident Assessment Instrument-Minimum Dataset version 2.0 (RAI-MDS 2.0).

SETTING AND

PARTICIPANTS

LTC residents in Ontario between January 1, 2016, and December 31, 2019.

METHODS

We used residents' first RAI-MDS 2.0 assessment in the study period as the index assessment. Probable delirium was identified via the delirium Clinical Assessment Protocol. Medication use in the 2 weeks preceding assessment was captured using medication claims data. PIP was measured using the STOPP/START criteria and 2015 Beers criteria, with residents classified as having 0, 1, 2, or 3+ instances of PIP. Relationships between PIP and probable delirium was assessed via bivariate and multivariable logistic regression models.

RESULTS

The study population included 171,190 LTC residents (mean age 84.5 years, 66.8% female, 62.9% with dementia). More than half (51.8%) of residents had 1+ instances of PIP and 21% had 3+ instances of PIP according to the STOPP/START criteria; PIP prevalence was slightly lower when assessed using Beers criteria (36.5% with 1+, 11.1% with 3+). Overall, 3.7% of residents had probable delirium. The prevalence of probable delirium increased as the number of instances of PIP increased, with residents with 3+ instances of STOPP/START PIP being 1.66 times more likely (95% CI 1.56-1.77) to have probable delirium compared to those with no instances of PIP. Similar findings were observed when PIP was measured using the Beers criteria. Central nervous system (CNS)-related PIP criteria showed a stronger association with probable delirium than non-CNS-related PIP criteria.

CONCLUSIONS AND IMPLICATIONS: This population-based study highlighted that PIP was highly prevalent in long-term care residents and was associated with an increased prevalence of probable delirium.