title: Differential Associations Between Delirium and Mortality According to Delirium Subtype and Age: A Prospective Cohort Study.
abstract: OBJECTIVE
  This study investigated the differential associations between delirium and mortality in terminally ill patients according to delirium subtype and age.
  
  
  METHODS
  This was a prospective cohort study of terminally ill patients. Delirium was diagnosed using the confusion assessment method. Delirium subtypes were defined based on Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition criteria and the Delirium Rating Scale-98-R. A multivariate Cox proportional hazards regression analysis was used to examine predictors of mortality.
  
  
  RESULTS
  Of the 322 cases, 98 patients (30.4%) were diagnosed as having delirium. The median (interquartile range) number of survival days after admission was 17.0 (10.0-36.0) days for patients with delirium and 28.0 (16.0-57.0) days for patients without delirium (p = .002). A multivariate analysis revealed that patients with hypoactive and mixed subtypes of delirium survived for shorter periods compared with patients without delirium (hazard ratio [HR] = 1.65 [95% confidence interval {CI} = 1.05-2.59, p = .029] and HR = 2.30 [95% CI = 1.44-3.69, p = .001], respectively). The hypoactive and mixed delirium subtypes exhibited significant interactions with age: younger age was associated with shorter periods of survival in patients with hypoactive and mixed subtype delirium (HR = 0.95 [95% CI = 0.93-0.98, p < .001] and HR = 0.97 [95% CI = 0.93-1.00, p = .038], respectively).
  
  
  CONCLUSIONS
  The hypoactive and mixed subtypes of delirium were associated with shorter survival periods in terminally ill patients, and these associations interacted significantly with age. These findings support the clinical and academic value of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition specifiers that differentiate the diagnoses of delirium subtypes.
authors.affiliation: From the Departments of Psychiatry (S.-Y. Kim, S.-W. Kim, J.-M. Kim, I.-S. Shin, K.-Y. Bae, J.-S. Yoon), and Hemato-Oncology (H.-J. Shim, W.-K. Bae, S.-H. Cho, I.-J. Chung), Chonnam National University Medical School, Gwangju, Republic of Korea; and Mental Health Clinic (S.-Y. Kim), Chonnam National University Hwasun Hospital, Hwasun, Republic of Korea.
authors.forename: Seon-Young
authors.initials: SY
authors.lastname: Kim
authors.forename: Sung-Wan
authors.initials: SW
authors.lastname: Kim
authors.forename: Jae-Min
authors.initials: JM
authors.lastname: Kim
authors.forename: Il-Seon
authors.initials: IS
authors.lastname: Shin
authors.forename: Kyung-Yeol
authors.initials: KY
authors.lastname: Bae
authors.forename: Hyun-Jeong
authors.initials: HJ
authors.lastname: Shim
authors.forename: Woo-Kyun
authors.initials: WK
authors.lastname: Bae
authors.forename: Sang-Hee
authors.initials: SH
authors.lastname: Cho
authors.forename: Ik-Joo
authors.initials: IJ
authors.lastname: Chung
authors.forename: Jin-Sang
authors.initials: JS
authors.lastname: Yoon
mesh_terms: D000368:Aged; D003693:Delirium / Q000145:classification / Q000453:epidemiology / Q000401:mortality; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012042:Registries; D019452:Terminally Ill / Q000706:statistics & numerical data*