# Companionship at hospital discharge and its association with subsequent delirium onset in older adults – the TRADE observational study

## TL;DR

This study examines how companionship during hospital discharge affects delirium in older adults, finding no direct link but highlighting the importance of delirium prevention.

## Contribution

The study introduces a new framework for evaluating cross-sectoral companionship and its potential impact on post-discharge delirium in older adults.

## Key findings

- Only 37.4% of participants reported optimal cross-sectoral companionship at discharge.
- Social contact and longer hospital stays were linked to better companionship, while alcohol use and ambulance transport were negative predictors.
- No association was found between optimal companionship and reduced delirium onset, but 20.7% of patients developed delirium within seven days.

## Abstract

Little is known about the role of cross-sectoral companionship (CSC) at hospital discharge or transfer to another facility/department and subsequent delirium incidence in older adults. We aimed to identify predictors of optimal CSC, and to evaluate its association with delirium incidence after discharge/transfer in this population.

Participants aged ≥ 70 years and their caregivers were recruited in four hospitals in Germany from 08/2019 to 02/2020, and asked standardized questionnaires prior to as well as 3, 7 and 90 days after discharge/transfer. CSC was classified according to its occurrence: before, during and/or after discharge/transfer, defined as optimal when reported before and after or before, during and after. Incident delirium was identified by confusion assessment method (CAM), family-CAM (FAM-CAM) and nursing delirium screening scale (Nu-DESC) (composite outcome). Logistic regression was performed to identify predictors of optimal CSC, and to evaluate the association between CSC and delirium.

Among 163 participants (median age 80.8 years, 55.8% women) 61 (37.4%) reported optimal CSC, with social contact with daughter and son-in-law and length of hospital stay identified as positive, and former alcohol consumption and transport by ambulance as negative predictors. Among 92 participants (median age 81.6 years, 56.5% women) with complete data on the presence or absence of delirium a 20.7% [95% CI 13.6; 30.0] 7-days delirium incidence proportion was observed. No association between optimal CSC and subsequent delirium onset was detected.

Only one third of patients reported optimal CSC at discharge/transfer, with social contact and length of hospital stay as positive, and former alcohol consumption and the use of an ambulance as negative predictors for an optimal CSC. Although no association between CSC and subsequent delirium could be identified in the present study, the fact that one fifth of discharged patients developed delirium highlights the importance of delirium-preventing measures around the time of discharge.

DRKS (Deutsches Register klinischer Studien) DRKS00017828. Registered on 17th September 2019.

The online version contains supplementary material available at 10.1186/s12877-026-07194-3.