Delirium Subtypes and Associated Characteristics in Older Patients With Exacerbation of Chronic Conditions

The prevalence and prognosis of delirium motor subtypes are not yet well established. We analyzed the prevalence of motor subtypes of delirium, as well as their risk factors and outcomes, among older vulnerable patients admitted for short-term management of exacerbated chronic conditions.

Cohort study of patients aged 65 and older who developed delirium while admitted to a subacute care unit for 12 months (N = 352). Confusion Assessment Method was used to determine the presence of delirium and the Delirium Motor Subtype Scale was used to define the motor subtype. Outcomes included discharge destination, mortality, readmission, and functional trajectories.

Out of 352 patients with delirium (mean age= 87.4, 73.6% with dementia), hyperactive delirium was the most prevalent subtype (40.6%), followed by mixed (31%), hypoactive (25.9%), and nonmotor (2.6%). In multivariate models, worse preadmission functional status (odds ratio [OR] [95% confidence interval {CI}] = 0.97 [0.96-0.98]) and higher comorbidity (OR [95% CI] = 1.3 [1.04-1.51]) were associated with an increased risk of hypoactive delirium. In multivariate models adjusted for different variables, including disability, hypoactive delirium was associated with mortality compared with hyperactive delirium (OR [95% CI] = 4.7 [1.6-14]) and mixed delirium (OR [95% CI] = 2.0 [1.02-3.9]) and with worse functional recovery (Beta[95% CI] = -0.2 [-12.0-(-0.4)]).

Delirium motor subtypes were associated with different patient characteristics and outcomes. Hypoactive delirium seems to affect more vulnerable patients and to be associated with worse outcomes. More research on the different delirium subtypes could help develop better preventive and management strategies.