Factors associated with delirium severity among older patients

The goal of this study was to determine whether the factors associated with delirium varied according to the severity of the delirium experienced by the older patients.

Delirium among older patients is prevalent and leads to numerous detrimental effects. The negative consequences of delirium are worse among older adults with severe delirium compared with patients with mild delirium. There has been no study identifying those factors associated with delirium severity among long-term care older patients newly admitted to an acute care hospital.

This is a descriptive study.

This is a secondary analysis study of institutionalized older patients newly admitted to an acute care hospital (n = 104). Upon admission, patients were screened for delirium with the Confusion Assessment Method and severity of delirium symptoms were determined by using the Delirium Index.

Of the 71 delirious older patients, 32 (45.1%) had moderate-severe delirium while 39 (54.9%) presented mild delirium. In univariate analyses, a significant positive relationship was observed between the level of prior cognitive impairment and the severity of delirium (p = 0.0058). Low mini-mental state examination (MMSE) scores (p < 0.0001), the presence of severe illness at the time of hospitalization (p = 0.0016) and low functional autonomy (BI: p = 0.0017; instrumental activities of daily living: p = 0.0003) were significantly associated with moderate-severe delirium. Older patients suffering from mild delirium used significantly more drugs (p = 0.0056), notably narcotics (p = 0.0017), than those with moderate-severe delirium. Results from the stepwise regression indicated that MMSE score at admission and narcotic medication use are the factors most strongly associated with the severity of delirium symptoms.

This present study indicates that factors associated with moderate-severe delirium are different from those associated with mild delirium. Given the result concerning the role of narcotics, future studies should evaluate the role of pain management in the context of delirium severity.

As moderate-severe delirium is associated with poorer outcomes than is mild delirium, early risk factor identification for moderate-severe delirium by nurses may prove to be of value in preventing further deterioration of those older patients afflicted with delirium.