Development and validation of an aetiology in delirium diagnostic support tool

Abstract

Background: recognition of the multifactorial causes of delirium represents a clinical challenge.

Objectives: to develop and show proof of principle of a diagnostic support tool (DST) for identification of causes of delirium.

Methods: stage 1-development of the aetiology in delirium-diagnostic support tool (AiD-DST); stage 2-validation of the AiD-DST against reference standard diagnosis, based on clinical assessment from two independent consultant geriatricians.

Results: a series of eight steps AiD-DST were formulated by an expert group to identify possible causes of delirium. Forty inpatients admitted to a general medical unit with a consultant physician/geriatrician diagnosis of delirium were recruited, consented and reviewed against the AiD-DST. Mean age was 85.1 (standard deviation 7.9) years and 26 (65%) of participants were female. Participants had multiple chronic co-morbidities [median Charlson Comorbidity Index 7; interquartile range (IQR 6-9)] and median number of medications was 8 (IQR 6-11.75). Median number of causes of delirium detected on AiD-DST was 3 (IQR 3-4) versus 5 (IQR 3-6) using the reference standard diagnosis, with sensitivity of 88.8% (95% confidence interval, 81.6-93.9%) and specificity of 71.8% (63-79.5%).

Conclusions: the aetiology in delirium DST shows promise in the identification of cause(s) in delirium.

Keywords: aetiology; algorithm; delirium; diagnosis; differential; older people.