Progression of delirium in advanced illness: a multivariate model of caregiver and clinician perspectives.

BACKGROUND Delirium is one of the most distressing and difficult to manage problems in advanced illness. Family caregivers have a unique view of the progression of delirium. OBJECTIVE This study examined precursors to delirium from the perspective of family caregivers. DESIGN This study utilized a two-stage concept mapping design that began with semistructured interviews with caregivers of patients suffering with delirium. The interview data was sorted and rated by clinicians prior to quantitative data analysis via multidimensional scaling (MDS) and cluster analysis. SUBJECTS/SETTINGS The subjects were 20 family caregivers of patients with a diagnosis of delirium in a hospice inpatient unit. RESULTS The main outcome of the study was a multidimensional model of precursors of delirium that included 99 specific items. The model included ten clusters within three general domains: Cognition, Distress, and Rest/Sleep. An exploratory analysis suggested that Rest and Sleep issues were evident to caregivers much earlier than other kinds of problems (mean=17.56 weeks prior to hospice admission, 95% CI=9.2-25.0 weeks). CONCLUSIONS This study provides detailed insights from family caregivers about the progression of delirium. The caregiver observations were clustered by multivariate analysis to provide a map of symptom domains. The principal finding of this study is that sleep disturbance was identified by almost all family caregivers much earlier than other more commonly recognized symptoms associated with delirium. The study highlights the importance of sleep fragmentation in the temporal progression of delirium and points toward opportunities for improved measurement, prevention, and treatment.