Delirium is a risk factor for further cognitive decline in cognitively impaired hip fracture patients

Arch Gerontol Geriatr. 2016 May-Jun;64:38-44. doi: 10.1016/j.archger.2015.12.004. Epub 2015 Dec 28.


Background: Delirium is a risk factor for dementia in cognitively intact patients. Whether an episode of delirium accelerates cognitive decline in patients with known dementia, is less explored.

Methods: This is a prospective follow-up study of 287 hip fracture patients with pre-fracture cognitive impairment. During the hospitalization, the patients were screened daily for delirium using the Confusion Assessment Method. Pre-fracture cognitive impairment was defined as a score of 3.44 or higher on the pre-fracture Informant Questionnaire on Cognitive Decline in the Elderly Short Form (IQCODE-SF). At follow-up after 4-6 months, the caregivers rated cognitive changes emerging after the fracture using the IQCODE-SF, and the patients were tested with the Mini Mental State Examination (MMSE). A sub-group of the patients had a pre-fracture MMSE score which was used to calculate the yearly decline on the MMSE in patients with and without delirium.

Results: 201 of the 287 patients developed delirium in the acute phase. In linear regression analysis, delirium was a significant and independent predictor of a more prominent cognitive decline at follow-up measured by the IQCODE-SF questionnaire (p=0.002). Among patients having a pre-fracture MMSE score, the patients developing delirium had a median (IQR) yearly decline of 2.4 points (1.1-3.9), compared to 1.0 points (0-1.9) in the group without delirium (p=0.001, Mann-Whitney test).

Conclusions: Hip fracture patients with pre-fracture dementia run a higher risk of developing delirium. Delirium superimposed on dementia is a significant predictor of an accelerated further cognitive decline.

Keywords: Cognitive trajectories; Delirium; Dementia; Hip fracture.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Cognition
  • Cognition Disorders / diagnosis*
  • Cognition Disorders / psychology
  • Delirium / diagnosis*
  • Dementia / diagnosis*
  • Dementia / psychology
  • Female
  • Follow-Up Studies
  • Hip Fractures / complications
  • Hip Fractures / psychology*
  • Hospitalization
  • Humans
  • Male
  • Neuropsychological Tests
  • Prospective Studies
  • Psychiatric Status Rating Scales
  • Regression Analysis
  • Retrospective Studies
  • Risk Factors
  • Sensitivity and Specificity
  • Surveys and Questionnaires