Journal of General Internal Medicine

, Volume 21, Issue 12, pp 1276–1281

Recoverable cognitive dysfunction at hospital admission in older persons during acute illness

Authors

    • Department of MedicineBeth Israel Deaconess Medical Center, Harvard Medical School
    • Aging Brain Center, Institute for Aging ResearchHebrew Senior Life
  • Ying Zhang
    • Department of MedicineBeth Israel Deaconess Medical Center, Harvard Medical School
    • Aging Brain Center, Institute for Aging ResearchHebrew Senior Life
  • Ling Han
    • Program on AgingYale University School of Medicine
  • Linda Leo-Summers
    • Program on AgingYale University School of Medicine
  • Richard Jones
    • Department of MedicineBeth Israel Deaconess Medical Center, Harvard Medical School
    • Aging Brain Center, Institute for Aging ResearchHebrew Senior Life
  • Edward Marcantonio
    • Department of MedicineBeth Israel Deaconess Medical Center, Harvard Medical School
    • Aging Brain Center, Institute for Aging ResearchHebrew Senior Life
Original Articles

DOI: 10.1111/j.1525-1497.2006.00613.x

Cite this article as:
Inouye, S.K., Zhang, Y., Han, L. et al. J GEN INTERN MED (2006) 21: 1276. doi:10.1111/j.1525-1497.2006.00613.x

Abstract

BACKGROUND: While acute illness and hospitalization represent pivotal events for older persons, their contribution to recoverable cognitive dysfunction (RCD) has not been well examined.

OBJECTIVE: Our goals were to estimate the frequency and degree of RCD in an older hospitalized cohort; to examine the relationship of RCD with delirium and dementia; and to determine 1-year cognitive outcomes.

DESIGN: Prospective cohort study.

PARTICIPANTS: Four hundred and sixty patients aged ≥70 years drawn from consecutive admissions to an academic hospital.

MEASUREMENTS: Patients underwent interviews daily during hospitalization and at 1 year. The primary outcome was RCD, defined as an admission Mini-Mental State Examination (MMSE) score that improved by 3 or more points by discharge.

RESULTS: Recoverable cognitive dysfunction occurred in 179 of 460 (39%) patients, with MMSE impairment at baseline ranging from 3 to 13 points (median=5.0 points). The majority of cases were not characteristic of either delirium or dementia, as 144 of 179 (80%) cases did not meet criteria for delirium, and 133 of 164 (81%) cases did not meet criteria for dementia at baseline. In multivariable analysis controlling for baseline MMSE level, 3 factors were predictive of RCD: higher educational level, preadmission functional impairment, and higher illness severity. At 1 year, further improvement in MMSE score occurred in 38 of 92 (41%) patients with RCD. Recoverable cognitive dysfunction was independently predictive of 1-year mortality with an adjusted odds ratio of 1.82 (95% confidence interval [95% CI] 1.03 to 3.20).

CONCLUSIONS: Acute illness is accompanied by a high rate of RCD that is neither characteristic of delirium or dementia. Our observations underscore the reversible nature of this cognitive dysfunction with continued improvement over the ensuing year, and highlight the potential clinical implications of this under-recognized phenomenon.

Key words

deliriumdementiacognitive impairmenthospitalizationgeriatrics

Copyright information

© the Society of General Internal Medicine 2006