Frequency, course, outcomes and factors associated with delirium among adult patients admitted to Uganda Cancer Institute

Abstract

Background: Delirium is a neurocognitive disorder that commonly affects patients with cancer. Among patients with cancer admitted to oncology units, the prevalence varies from 18% to 33% and the incidence varies from 3.5% to 16.5%. The overall incidence of cancer has gradually increased not only worldwide but also in Uganda. Few studies on delirium in patients with cancer have been conducted in our setting. Objectives: This study aimed to investigate the frequency, course and outcome of delirium during a 1-week period after diagnosis, and factors associated with delirium among adult patients admitted to Uganda Cancer Institute (UCI). Methods: This longitudinal study was carried out among adult patients (≥18 years) admitted to UCI with cancer. A socio-demographic questionnaire to document the patient characteristics, the Confusion Assessment Method (CAM) to diagnose delirium, and the Delirium Rating Scale-Revised 98 (DRS-R98) to define the course of delirium were used. Bivariate and Multivariate analyses were done to describe associations between dependent and independent variables. Results: On admission, 26 out of 237 (11%) patients were diagnosed with delirium. On day 3, 10 out of 211 (5%) patients had developed delirium and on day 7, 1 out 131 (1%) patients had developed delirium. The most common type of delirium was hypoactive delirium. The mortality was significantly higher among patients with delirium (32.1%) than those without delirium (2.6%) (p=<0.001). Of the patients who completed the 7-day follow up period; the mean severity of delirium decreased with time and majority achieved resolution (57.1%) – majority of them had mixed delirium. The risk of developing delirium was associated with: a low functional status (Eastern Cooperative Oncological Group Performance Status (ECOG PS) 3 and 4) (RR= 1.99, p=0.002), hypertension (RR=2.08, p=0.033), use of corticosteroids (RR=2.70, p=0.019), and liquid cancer (RR= 2.09, p= 0.023). Conclusion: The prevalence of delirium in this study was clinically significant and higher than that observed in patients on general medical wards. However, it was lower than the prevalence reported among patients with cancer in other studies, which included older patients with more advanced stages of the disease. Patients with delirium have increased mortality and low discharge rates. Delirium is associated with a low functional status (ECOG PS 3 and 4), hypertension, use of corticosteroids and liquid cancer. Our findings highlight the importance of early detection and management of delirium among patients with cancer.