# Increased mortality in dementia patients using inhaled anticholinergics: A nationwide register study from the Swedish registry on dementia/cognitive disorders, SveDem

## TL;DR

This study found that dementia patients using inhaled anticholinergics had higher mortality rates, possibly due to their underlying COPD.

## Contribution

The study is the first to explore the link between inhaled anticholinergics and mortality in dementia patients using nationwide data.

## Key findings

- Dementia patients using inhaled anticholinergics had higher standardized mortality rates across all age groups.
- Exposed patients had a 73% higher risk of death compared to non-users.
- The association may be driven by the underlying COPD rather than the medication itself.

## Abstract

Patients with chronic obstructive pulmonary disease (COPD) face increased risks of cognitive impairment and mortality compared with the general population. Inhaled anticholinergics (LAMA/SAMA) are central in COPD treatment. The link between COPD and dementia is well studied, while effects of COPD medications on survival in dementia patients, have received limited attention.

Describe dementia patients using LAMA/SAMA in the Swedish Dementia Registry (SveDem) and compare survival between users (exposed) and non-users (unexposed).

This register-based study used data from SveDem and the Swedish Prescribed Drug Register to identify dementia patients using inhaled anticholinergics. All patients diagnosed with dementia between 2008-01-01 and 2017-12-31 were included. Exposed patients had at least one LAMA/SAMA dispensation per year in the two years prior the index date or more than one in the year before. Standardized-mortality-rates (SMR) were calculated, and survival analysed using Kaplan-Meier and Cox regression.

A total of 74,018 dementia patients were included, of whom 3.5% had used inhaled anticholinergics. Alzheimer's disease was the most common dementia type. SMR was higher in exposed patients across all age groups: 8.21 versus 4.08 (ages 61–75) and 2.94 versus 1.84 (ages 75–90). Exposed had a higher risk of death (crude HR 1.73, 95% CI: 1.62–1.86) compared to unexposed.

In this register-based study we observed an association between inhaled anticholinergic use and reduced survival in dementia patients. This association is thought to be mainly driven by the underlying disease, COPD. Further studies are needed to clarify effects of inhaled anticholinergics on survival.