Preliminary evidence of impaired thinking in sick patients

Ann Intern Med. 2001 Jun 19;134(12):1120-3. doi: 10.7326/0003-4819-134-12-200106190-00012.


Background: Earlier anecdotal observations suggested to us that certain aspects of judgment in sick adults approximate the thinking of children.

Objective: To describe changes in judgment associated with serious illness in otherwise competent adults.

Design: Cohort study.

Setting: Urban acute-care hospital and senior citizen center.

Participants: Sicker (Karnofsky score </= 50; n = 24) and less sick (Karnofsky score > 50; n = 39) hospitalized patients were compared with controls (n = 28). Normal performance on the Mini-Mental State Examination (score >/= 24) was required for study entrance.

Measurements: Seven Piagetian tasks of judgment designed to study childhood cognitive development. Degree of sickness was determined by using the Karnofsky scale of physical function.

Results: Patients with Karnofsky scores of 50 or less responded correctly to fewer Piagetian tasks than controls (mean [+/-SD], 1.8 +/- 2.6 vs. 5.9 +/- 1.6; P < 0.001). Furthermore, a smaller proportion of sicker patients responded correctly to each of the seven tasks. Patients with Karnofsky scores greater than 50 did not perform differently than controls.

Conclusion: In sicker hospitalized patients, performance on seven Piagetian tasks of judgment was similar to that among children younger than 10 years of age. This evidence of cognitive impairment warrants further investigation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Case-Control Studies
  • Cognition Disorders / etiology*
  • Cohort Studies
  • Disease / psychology*
  • Hospitalization
  • Humans
  • Mental Status Schedule
  • Severity of Illness Index
  • Statistics, Nonparametric