# Patients With Dementia Undergoing High-Risk Inpatient Surgery Have Poor Outcomes

## TL;DR

Patients with dementia who undergo high-risk surgery have significantly worse outcomes, including higher mortality and complications, compared to those without dementia.

## Contribution

This study provides national data showing that dementia is associated with worse post-surgery outcomes, offering insights for clinical decision-making.

## Key findings

- Ninety-day mortality was 22.8% for dementia patients versus 9.3% for non-dementia patients.
- Dementia patients were more likely to have major complications and be discharged to higher-level care.
- They were also more likely to have prolonged skilled nursing facility stays.

## Abstract

Surgery is common among patients living with dementia, and understanding outcomes may help decision-making. We compared patients’ and utilization outcomes after high-risk surgery among patients with and without dementia.

In this retrospective national cohort study, we compared outcomes of Medicare fee-for-service beneficiaries 66 years or older who underwent high-risk inpatient surgery (i.e., with an inpatient mortality of at least 1%) from January 1, 2017 to September 30, 2018. We examined 90- and 30-day all-cause mortality, major complications, discharge to a higher level of care, intensive end-of-life interventions, and prolonged skilled nursing facility (SNF) stay. We used generalized estimating equations regression modeling and competing risks analysis.

Among 19,998,187 beneficiaries, we identified 859,570 who had fee-for-service coverage and were 66 years or older at the time of a high-risk surgery. Of these, 124,822 (14.5%) had a diagnosis of dementia. Female sex accounted for 81,252 (65.1%) of the dementia cohort. Four of five of the most common procedures were related to femur fracture and cardiac surgery in the dementia and non-dementia cohorts. Ninety-day mortality was worse among patients with dementia: 22.8% versus 9.3% (adjusted odds ratio [aOR] 1.82, 95% confidence interval [CI] 1.78–1.85). Patients with dementia were also more likely to have major complications (51.6% vs. 38.5%, aOR 1.19, 95% CI 1.17–1.20), be discharged to a higher level of care (75.1% vs. 41.3%, aOR 1.49, 95% CI 1.44–1.53), and have a prolonged SNF stay (3.7% vs. 1.4%, aOR 1.80, 95% CI 1.69–1.91). Although patients with ADRD were overall less likely to receive intensive interventions during the index admission and at 90 days, they were more likely to receive feeding tubes (aOR 1.22, 95% CI 1.17–1.28).

Persons living with dementia experience a broad range of worse outcomes after high-risk surgery compared to those without dementia. These data may be used for decision-making.