Risk Factors Associated with the Severity of Delirium

Seo, Young Eun; Kim, Tae Suk; Won, Wang Yun; Lee, Chang Uk; Lee, Chul

Abstract

OBJECTIVES
The purpose of this study was to investigate the relationship between the sum of the risk factors for delirium and the severity of delirium and to identify those risk factors which increase the severity of delirium.
METHODS
The participants were 151 patients who were consulted with a consultation-liaison psychiatrist and diagnosed using DSM-IV criteria as suffering from delirium. Sociodemographic and clinical characteristics were obtained through structured interviews and medical chart reviews. The severity of delirium symptoms was measured by the Korean version of the Delirium Rating Scale-Revised 98 (K-DRS-R98). Patients were divided into two groups : a 'mild delirium group (MDG)', whose total scores on the K-DRS-R98 were below 16, and a 'severe delirium group (SDG)' with the scores above 16.
RESULTS
There was a positive correlation between the sum of known risk factors for delirium and total scores on the K-DRS-R98 (p=0.009). The SDG showed a significantly higher incidence of abnormal potassium levels, abnormal sodium levels, old age, and polypharmacy than the MDG (p=0.010, p=0.046, p=0.042, and p=0.033 respectively). In a logistic regression model, old age, abnormal sodium and potassium levels, and polypharmacy were found to predict increased severity of the delirium (p=0.001, p=0.007, p=0.019, and p=0.005 respectively).
CONCLUSION
The present findings suggested that there are certain factors which not only affect the occurrence of delirium, but also severity of delirium symptoms.