BACKGROUND

Delirium is a common and distressing neurocognitive condition that frequently affects patients in palliative care settings and is often underdiagnosed.

AIM

Expanding on a 2013 review, this systematic review examines the incidence and prevalence of delirium across all palliative care settings.

DESIGN

This systematic review and meta-analyses were prospectively registered with PROSPERO and included a risk of bias assessment.

DATA SOURCES

Five electronic databases were examined for primary research studies published between 1980 and 2018. Studies on adult, non-intensive care and non-postoperative populations, either receiving or eligible to receive palliative care, underwent dual reviewer screening and data extraction. Studies using standardized delirium diagnostic criteria or valid assessment tools were included.

RESULTS

Following initial screening of 2596 records, and full-text screening of 153 papers, 42 studies were included. Patient populations diagnosed with predominantly cancer ( = 34) and mixed diagnoses ( = 8) were represented. Delirium point prevalence estimates were 4%-12% in the community, 9%-57% across hospital palliative care consultative services, and 6%-74% in inpatient palliative care units. The prevalence of delirium prior to death across all palliative care settings ( = 8) was 42%-88%. Pooled point prevalence on admission to inpatient palliative care units was 35% (confidence interval = 0.29-0.40,  = 14). Only one study had an overall low risk of bias. Varying delirium screening and diagnostic practices were used.

CONCLUSION

Delirium is prevalent across all palliative care settings, with one-third of patients delirious at the time of admission to inpatient palliative care. Study heterogeneity limits meta-analyses and highlights the future need for rigorous studies.