Prognostic significance of delirium subtypes in critically ill medical and surgical patients: a secondary analysis of a prospective multicenter study

Table 3 Association of delirium subtypes and covariates with hospital mortality

Variable	Mortality odds ratio (95% CI), unadjusted^a	p value	Mortality odds ratio (95% CI), adjusted^b	p value
Delirium subtypes (predictor of interest)^c
No delirium (reference)
Hypoactive subtype	1.36 (0.91–2.05)	0.139	1.34 (0.71–2.55)	0.37
Mixed subtype	2.51 (1.66–3.78)	0.001	3.09 (1.79–5.33)	0.001
Covariates
Age	1.04 (1.03–1.05)	0.001	1.03 (1.02–1.04)	0.001
APACHE IV^d	1.05 (1.04–1.05)	0.001	1.05 (1.05–1.06)	0.001
Elective surgery (reference)
Medical	5.84 (3.61–9.45)	0.001	2.55 (1.46–4.46)	0.001
Emergency surgery	4.06 (2.28–7.21)	0.001	1.91 (1.00–3.67)	0.05
No delirium*APACHE IV (reference)^d
Hypoactive subtype*APACHE IV	0.97 (0.95–0.99)	0.001	0.97 (0.96–0.99)	0.001
Mixed subtype*APACHE IV	0.96 (0.94–0.97)	0.001	0.96 (0.94–0.97)	0.001

^aAnalyzed with logistic regression analysis, after multiple imputation with the mice package in R
^bLogistic mixed-effect model, adjusted for centered APACHE IV score and its interaction with delirium subtype, age and admission diagnosis, and a random intercept for hospital
^cHospital mortality in the no delirium group was 11.9% (n = 136), in patients with the hypoactive subtype 16.9% (n = 31) and in those with mixed subtype 26.3% (n = 36). Patients with hyperactive subtype (n = 28) were excluded from the analysis due to its low incidence, precluding meaningful statistical analysis. Hospital mortality occurred in 7 of these patients (25.9%). For 4 patients delirium subtype was unknown
^dAPACHE IV scores [20] range from 0 (best) to 286 (worst), based on the most abnormal values observed during 24 h following ICU admission. For the primary adjusted analysis, a centered APACHE IV score was used, as calculated by subtracting the mean APACHE IV score from the individual APACHE IV scores

ISSN: 2052-0492