Retrospective delirium ascertainment from case notes: a retrospective cohort study

Abstract

Objectives: This study sets out to ascertain if recognition of delirium impacts on patient outcomes.

Design: Retrospective cohort study.

Setting: Unscheduled admissions to acute care trust/secondary care UK hospitals.

Participants: Six hundred and fifty-six older adults aged ≥65 years admitted on 14 September 2018.

Measurements: Delirium was ascertained retrospectively from case notes using medical notes. Documented delirium was classified as recognised delirium and retrospectively ascertained delirium was classified as unrecognised delirium.

Primary and secondary outcome measures: Primary outcome measure: inpatient mortality.

Secondary outcome measures: length of stay, discharge destination.

Results: Delirium was present in 21.1% (132/626) of patients at any point during admission. The presence of delirium was associated with increased mortality (HR 2.65, CI 1.40 to 5.01). Recognition of delirium did not significantly impact on outcomes.

Conclusions: Delirium is associated with adverse outcomes in hospitalised older adults. However, there is insufficient evidence that recognition of delirium affects outcomes. However, delirium recognition presents an opportunity to discuss a person's overall prognosis and discuss this with the patient and their family. Further research is needed to assess the pathophysiology of delirium to enable development of targeted interventions towards improved outcomes in patients with delirium.

Keywords: delirium & cognitive disorders; geriatric medicine; medical education & training.

Figure 1

Criteria used for retrospective delirium diagnosis as adapted from DSM-5. A diagnosis of probable delirium was made in retrospective case notes reviewed in patients who satisfied criteria of ‘yes’ to a, b, c and e, and ‘no’ to d. DSM-5, Diagnostic and Statistical Model of Diseases, fifth edition. AMTS = Abbreviated Mental Test Score; MOCA = Montreal Cognitive Assessment

Figure 2

Flowchart of patient identification and delirium diagnosis. Case notes were reviewed in 656 patients, of whom 75 had a recognised diagnosis of delirium and a further 57 were considered to have unrecognised delirium.