Article Text
Abstract
Introduction Delirium is a serious neuropsychiatric syndrome, which is common amongst terminally ill patients. It often goes underdiagnosed and undertreated. Early detection may improve patient outcomes. The 4 ‘A’s Test (4AT, www.the4AT.com) is a brief tool for delirium detection in routine clinical practice. It has been validated in 25 studies involving more than 5000 observations. The test is currently used in specialist palliative care units but has not been validated in this setting. The aim of the study was to determine the diagnostic accuracy of the 4AT against a reference standard in hospice inpatients.
Aims The aim of the study was to determine the diagnostic accuracy of the 4AT against a reference standard in hospice inpatients.
Methods Test validation study conducted in 2 hospice inpatient units in Scotland, UK. Participants underwent the 4AT and a reference standard, based on the diagnostic delirium criteria in the fifth edition of Diagnostic and Statistical Manual of Mental Disorders (DSM-5). The assessments were conducted, in a randomized order, by pairs of independent raters, who were blinded to the results of the other assessment.
Results 148 individuals were recruited, including 14% (19/148) who required a legal proxy to consent on their behalf. 137 participants completed both assessments. Of these, 93% had cancer as their primary diagnosis. Mean age was 70.4 (SD 10.6) years and Karnofsky performance status scale was 44% (SD 14.9). 50% (69/137) of participants died during this hospice admission and 36% (49/137) were discharged home or to another care setting. The outcome was unknown for 14% (19/137). Three participants had an indeterminate diagnosis, so were excluded from analysis. Overall, 33% (44/134) had delirium according to the reference standard assessment. The 4AT had a sensitivity of 88% and a specificity of 94%.
Conclusions The 4AT is a short delirium detection tool, that can be used to detect delirium in patients receiving palliative care. Routine delirium screening using the 4AT on admission to a hospice service is recommended.
Trial Registration International standard randomised controlled trial number (ISRCTN) 97417474.
Conflict of Interest Statement AMJM led the design of the 4AT in 2011 (with others, see www.the4AT.com); note that the 4AT is free to download and use.