ORIGINAL COMMUNICATION Delirium in acute stroke: screening tools, incidence rates and predictors: a systematic review G. Carin-Levy • G. E. Mead • K. Nicol • R. Rush • F. van Wijck Received: 14 September 2011 / Accepted: 15 December 2011 / Published online: 11 January 2012 Ó Springer-Verlag 2012 Abstract Delirium is a common complication in acute stroke yet there is uncertainty regarding how best to screen for and diagnose delirium after stroke. We sought to establish how delirium after stroke is identified, its inci- dence rates and factors predicting its development. We conducted a systematic review of studies investigating delirium in acute stroke. We searched The Cochrane Col- laboration, MEDLINE, EMBASE, CINHAL, PsychINFO, Web of Science, British Nursing Index, PEDro and OT Seeker in October 2010. A total of 3,127 citations were screened, full text of 60 titles and abstracts were read, of which 20 studies published between 1984 and 2010 were included in this review. The methods most commonly used to identify delirium were generic assessment tools such as the Delirium Rating Scale (n = 5) or the Confusion Assessment Method (n = 2) or both (n = 2). The incidence of delirium in acute stroke ranged from 2.3–66%, with our meta-analysis random effects approach placing the rate at 26% (95% CI 19–33%). Of the 11 studies reporting risk factors for delirium, increased age, aphasia, neglect or dysphagia, visual disturbance and elevated cortisol levels were associated with the development of delirium in at least one study. The outcomes associated with the condition are increased morbidity and mortality. Delirium is found in around 26% of stroke patients. Difference in diagnostic and screening procedures could explain the wide variation in frequency of delirium. There are a number of factors that may predict the development of the condition. Keywords Delirium Á Acute stroke Á Diagnosis and screening Introduction Delirium (or acute confusional state) is a severe but potentially preventable disorder which is common among elderly hospital patients [1, 2], with reported prevalence of 20–30% across a variety of settings [3]. Delirium is asso- ciated with increased mortality, morbidity and length of hospital stay [4, 5]. Delirium may be hyperactive (accompanied by overt psychotic symptoms and agitation); hypoactive (characterised by sedation); or mixed (i.e. both hypoactive and hyperactive). The hypoactive type can often be undetected or misdiagnosed as depression [6]. Although stroke is a recognised predisposing factor for the development of delirium, there is currently no clear guidance on whether stroke patients should be routinely screened for delirium, no guidelines on the best way to screen for delirium and no multidisciplinary treatment recommendations for the condition [7, 8]. This is despite recent national guidance on the importance of early iden- tification of delirium in hospital patients over the age of 65 presenting with significant illness [9]. Potentially, this means that delirium in acute stroke may be missed, par- ticularly the hypoactive type [10]. There is, to our knowledge, no published systematic review on delirium after stroke. As a systematic review is G. Carin-Levy (&) Á K. Nicol Á R. Rush School of Health Sciences, Queen Margaret University, Queen Margaret University Drive, Edinburgh EH21 6UU, UK e-mail: GCarin-Levy@qmu.ac.uk G. E. Mead Geriatric Medicine, Clinical and Surgical Sciences, The University of Edinburgh, Edinburgh, UK F. van Wijck Institute for Applied Health Research and School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, UK 123 J Neurol (2012) 259:1590–1599 DOI 10.1007/s00415-011-6383-4