Validity and reliability of the Johns Hopkins Adapted Cognitive Exam for critically ill Patients

John J. Lewin, Shannon N. Ledroux, Kenneth M Shermock, Carol Thompson, Haley E. Goodwin, Erin A. Mirski, Randeep S. Gill, Marek A Mirski

Research output: Contribution to journalArticle

Abstract

Objective: To validate The Johns Hopkins Adapted Cognitive Exam Designed to assess and quantify cognition in critically ill Patients. Design: Prospective cohort study. Setting: Neurosciences, surgical, and medical intensive care units at The Johns Hopkins Hospital. Patients: One hundred six adult critically ill Patients. Interventions: One expert neurologic assessment and four Measurements of the Adapted Cognitive Exam (all Patients). Four Measurements of the Folstein Mini-Mental State Examination in nonintubated Patients only. Adapted Cognitive Exam and Mini-Mental State Examination were performed by 76 different raters. Measurements and Main Results: One hundred six Patients were assessed, 46 intubated and 60 nonintubated, resulting in 424 Adapted Cognitive Exam and 240 Mini-Mental State Examination Measurements. Criterion validity was assessed by comparing Adapted Cognitive Exam with a neurointensivist's assessment of cognitive status (ρ = 0.83, p <.001). Ordinal logistic regression established optimal predicted cut points for cognitive status classification (≤28 = severely impaired, 29-55 = moderately impaired, ≥ 56 = mildly impaired or normal). Using these cut points, the Adapted Cognitive Exam appropriately classified cognitive status 90% of the time. Construct validity was assessed by comparing Adapted Cognitive Exam with Mini-Mental State Examination in nonintubated Patients (ρ = 0.81, p <.001). Face validity was assessed by surveying raters who used both the Adapted Cognitive Exam and Mini-Mental State Examination and indicated the Adapted Cognitive Exam was an accurate reflection of the patient's cognitive status, more sensitive a marker of cognition than the Mini-Mental State Examination, and easy to use. The Adapted Cognitive Exam demonstrated excellent interrater reliability (intraclass correlation coefficient = 0.997; 95% confidence interval 0.997-0.998) and interitem reliability of each of the five subscales of the Adapted Cognitive Exam and Mini-Mental State Examination (Cronbach's α: range for Adapted Cognitive Exam = 0.83-0.88; range for Mini-Mental State Examination = 0.72-0.81). Conclusion: The Adapted Cognitive Exam is the first valid and reliable examination for the assessment and quantification of cognition in critically ill Patients. It provides a useful, Objective tool that can be used by any member of the interdisciplinary critical care team to support clinical assessment and research efforts.

Original languageEnglish (US)
Pages (from-to)139-144
Number of pages6
JournalCritical Care Medicine
Volume40
Issue number1
DOIs
StatePublished - Jan 2012

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Keywords

  • Brain injuries
  • Cognition
  • Critical care
  • Critical ill-ness
  • Neurological examination
  • Validation studies

ASJC Scopus subject areas

  • Critical Care and Intensive Care Medicine

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