Relationship between cognitive status at admission and incident delirium in older medical inpatients

J Neuropsychiatry Clin Neurosci. 2010 Summer;22(3):329-37. doi: 10.1176/jnp.2010.22.3.329.


To evaluate the relationship between cognitive status and incident delirium, 291 geriatric patients on internal medicine wards were evaluated on admission with the Mini-Mental State Examination (MMSE) and Confusion Assessment Method-Spanish. Those with incident delirium were assessed using the Delirium Rating Scale-Revised-98 (DRS-R98). Delirium incidence was 11.7%, and 82 patients (28.2%) had cognitive deficits on MMSE. As cognitive impairment worsened, the risk for delirium increased linearly, and for each unit of MMSE worsening the DRS-R98 severity score worsened 0.4 points (F=5.39, df=1, p=0.027). Optimal MMSE cutoff score from receiver-operating characteristic curve analysis was 24.5. Even mild cognitive deficits increase delirium risk and severity.

MeSH terms

  • Age Factors
  • Aged
  • Aged, 80 and over
  • Case-Control Studies
  • Cognition Disorders / complications
  • Cognition Disorders / diagnosis*
  • Cognition Disorders / psychology
  • Delirium / diagnosis*
  • Delirium / etiology
  • Delirium / psychology
  • Female
  • Geriatric Assessment*
  • Humans
  • Inpatients / psychology*
  • Male
  • Middle Aged
  • Patient Admission
  • Patient Selection
  • Psychiatric Status Rating Scales
  • Risk Factors
  • Severity of Illness Index
  • Statistics, Nonparametric