Three core domains of delirium validated using exploratory and confirmatory factor analyses

Area of Science:

• Geriatric Medicine
• Neuroscience
• Psychiatry

Background:

• Delirium is a common neuropsychiatric disorder characterized by acute fluctuations in attention and cognition.
• The underlying symptom structure of delirium requires further elucidation for accurate diagnosis and management.
• Previous research proposed three core symptom domains: circadian rhythm disturbances, higher-level thinking impairment, and cognitive deficits.

Purpose of the Study:

• To empirically validate the proposed three-core symptom domains of delirium.
• To analyze the factor structure of delirium symptoms using the Delirium Rating Scale-Revised-98 (DRS-R98).

Main Methods:

• Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were performed on a pooled international dataset of 592 patients.
• The analysis utilized data from 14 studies employing DSM-IV criteria and the DRS-R98 scale.
• A stepwise analysis involved EFA (n=100), CFA-modeling (n=246), and CFA-validation (n=246) to assess reliability and fit.

Main Results:

• EFA revealed that DRS-R98 items representing core delirium symptoms loaded onto a single factor, supporting their cohesive nature.
• Two CFAs confirmed a three-domain structure (circadian, higher-level thinking, cognitive) with high item loadings (>0.7) and good statistical fit.
• Attention, thought process, and sleep-wake cycle/motor behavior demonstrated the highest loadings within their respective domains.

Conclusions:

• The study confirms and validates the proposed three-core symptom domains of delirium: circadian, higher-level thinking, and cognitive.
• These domains are highly related to their hypothesized symptom representations and align with the concept of impaired consciousness in delirium.
• The validated domains should be incorporated into clinical and research assessments of delirium.