Development and validation of a tool for assessing understanding of brain death.

BACKGROUND Death by neurological criteria is often misunderstood by laypersons even though they make decisions about withdrawal of care and organ donation. No validated questionnaire for determining laypersons' understanding of brain death exists. Such a tool could be useful in clinical, educational, and research settings. METHODS Brain death experts and a focus group of laypersons were used to develop a 5-item questionnaire with face validity. The questionnaire explores 3 concepts: apnea, irreversibility, and differentiation between cardiac death, brain death, and persistent vegetative state. The questionnaire was administered to separate groups of laypersons and experts and was readministered 7 to 10 days later. Test-retest reliability for individual items and overall score was measured by using Spearman rank correlation. Internal consistency of the questionnaire was measured by using Cronbach alpha. Utility of the questionnaire in discriminating between scores of laypersons and experts was evaluated by using a t test. RESULTS Twelve laypersons and 13 experts participated. The test-retest correlation was significant for all questions (Spearman p range, 0.43-0.94) and raw score (Spearman p=0.91, P<.001). Internal consistency was fair (Cronbach alpha=0.64). The questionnaire enabled discrimination of laypersons from experts, with mean (SD) raw scores of 3.0 (1.1) vs 4.8 (0.6), respectively (t test, P<.001). Removal of 1 item improved internal consistency (Cronbach alpha=0.70), but with a corresponding decrease in discriminatory ability. CONCLUSIONS This simple 5-item questionnaire for evaluating understanding of brain death has test-retest reliability, internal consistency, and can be used to discriminate between persons who do and do not understand brain death.