Delirium prevalence, incidence, and implications for screening in specialist palliative care inpatient settings: A systematic review

BACKGROUND: Delirium is a serious neuropsychiatric syndrome frequently experienced by palliative care inpatients. This syndrome is under-recognized by clinicians. While screening increases recognition, it is not a routine practice. AIM AND DESIGN: This systematic review aims to examine methods, quality, and results of delirium prevalence and incidence studies in palliative care inpatient populations and discuss implications for delirium screening. DATA SOURCES: A systematic search of the literature identified prospective studies reporting on delirium prevalence and/or incidence in inpatient palliative care adult populations from 1980 to 2012. Papers not in English or those reporting the occurrence of symptoms not specifically identified as delirium were excluded. RESULTS: Of the eight included studies, the majority (98.9%) involved participants (1079) with advanced cancer. Eight different screening and assessment tools were used. Delirium incidence ranged from 3% to 45%, while delirium prevalence varied, with a range of: 13.3%-42.3% at admission, 26%-62% during admission, and increasing to 58.8%-88% in the weeks or hours preceding death. Studies that used the Diagnostic and Statistical Manual-Fourth Edition reported higher prevalence (42%-88%) and incidence (40.2%-45%), while incidence rates were higher in studies that screened participants at least daily (32.8%-45%). Hypoactive delirium was the most prevalent delirium subtype (68%-86% of cases). CONCLUSION: The prevalence and incidence of delirium in palliative care inpatient settings supports the need for screening. However, there is limited consensus on assessment measures or knowledge of implications of delirium screening for inpatients and families. Further research is required to develop standardized methods of delirium screening, assessment, and management that are acceptable to inpatients and families.