Association between Malnutrition and Delirium in Older Chronic Kidney Disease Patients Admitted to Intensive Care Units: A Data Linkage Study

Background: Independently, malnutrition and delirium in older hospitalised adults is prevalent. However, there is limited evidence on the association between these two conditions in older hospitalised adults with chronic kidney disease (CKD). Objectives: To determine the association between malnutrition and delirium in older CKD patients admitted to intensive care units (ICU). Methods: This data linkage study utilised administrative data from New South Wales (NSW) hospitals in Australia between 2017 and 2020. Admitted patient data was linked with Cause of Death Unit Record File, and NSW Registry of Deaths (RBD). The study population comprised all CKD patients aged 65 and over admitted to ICUs. Descriptive statistics were used to summarise patient characteristics. Binary logistic tested for association between malnutrition and delirium. Results: The study population included 748 CKD patients with a total 948 admissions in the study period. The International Statistical Classification of Diseases and Related Health Problems 10th Revision (ICD-10) was used to code for all outcomes and comorbidities. The incidence of delirium was 15.5% (n=141) and malnutrition was recorded in 11.3% (n=103) across all admissions. The adjusted odds ratio (OR) of a delirium diagnosis was 2.07 (95% CI: 1.27–3.39) for CKD patients that were malnourished compared to non-malnourished CKD patients. Conclusions: This study showed a significant association between delirium and malnutrition in older CKD patients admitted to ICU. Management of malnutrition could be critical in reducing the risk of delirium in older hospitalized patients with CKD. Additionally, more education and awareness around delirium and its association with malnutrition are needed in clinical practice.