Delirium superimposed on dementia: A quantitative and qualitative evaluation of patient experience

Delirium superimposed on dementia is common and is associated with adverse outcomes. Yet little is known about the patients' personal delirium experiences. We used quantitative and qualitative methods to assess the delirium superimposed on dementia experience among older patients.

We conducted a prospective cohort study among patients with delirium superimposed on dementia who were admitted to a rehabilitation ward. Delirium was diagnosed using DSM-IV-TR criteria. Delirium severity and symptoms were evaluated with the Delirium-O-Meter (D-O-M). The experience of delirium was assessed after delirium resolution (T0) and one month later (T1) with a standardized questionnaire and a qualitative interview. Level of distress was measured with the Delirium Experience Questionnaire.

Of the 30 patients included in the study, 50% had mild dementia; 33% and 17% had moderate and severe dementia. Half of the patients had evidence of the full range of D-O-M delirium symptoms. We evaluated 30 patients at T0 and 20 at T1. At T0, half of the patients remembered being confused as part of the delirium episode, and reported an overall moderate level of related distress. Patients reported high distress related to memories of anxiety/fear, delusions, restlessness, hypokinesia, and impaired orientation. Qualitative interviews revealed six main aspects of patient delirium experiences: Emotions; Cognitive Impairment; Psychosis; Memories; Awareness of Change; and Physical Symptoms.

The study provides novel information on the delirium experience in patients with dementia. These findings are the key for health care providers to improve the everyday care of this important group of frail older patients.