Preliminary Evidence of Impaired Thinking in Sick Patients

Preliminary Evidence of Impaired Thinking in Sick Patients

From the Joan and Sanford I. Weill College of Medicine of Cornell University, New York, New York; and Lynbrook Public School System, Lynbrook, New York.

Abstract

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.

Article and Author Information

Grant Support: By a grant from the New York Bar Foundation.
Acknowledgments: The authors thank Drs. Joseph A. Glick and Martha J. Hadley for sharing their knowledge of the measurement of judgment and the meaning of Piaget's tests.
Requests for Single Reprints: Eric J. Cassell, MD, 28 Old Fulton Street, Brooklyn, NY 11201; e-mail, ecassell{at}email.msn.com.
Current Author Addresses: Dr. Cassell: 28 Old Fulton Street, Brooklyn, NY 11201.
Dr. Leon: Department of Psychiatry, Joan and Sanford I. Weill College of Medicine of Cornell University, 1300 York Avenue, New York, NY 10021.
Dr. Kaufman: Lynbrook Public School System, 111 Atlantic Avenue, Lynbrook, NY 11563.
Author Contributions: Conception and design: E.J. Cassell, A.C. Leon, S.G. Kaufman.
Analysis and interpretation of the data: E.J. Cassell, A.C. Leon.
Drafting of the article: E.J. Cassell, A.C. Leon, S.G. Kaufman.
Critical revision of the article for important intellectual content: E.J. Cassell, A.C. Leon.
Final approval of the article: E.J. Cassell, A.C. Leon.
Provision of study materials or patients: S.G. Kaufman.
Statistical expertise: A.C. Leon.
Obtaining of funding: E.J. Cassell.
Administrative, technical, or logistic support: E.J. Cassell, S.G. Kaufman.
Collection and assembly of data: E.J. Cassell, S.G. Kaufman.