title: Defining 'recovery' for delirium research: a systematic review.
abstract: BACKGROUND
  Delirium is a common neuropsychiatric disorder. The natural course is of an acute, fluctuating and often transient condition; however, accumulating evidence suggests that delirium can be associated with incomplete recovery. Despite a growing body of research, a lack of clarity exists regarding definition and outcomes.
  
  
  OBJECTIVE
  To clarify the definition of recovery of delirium used in the literature.
  
  
  METHODS
  A Medline search was performed using relevant keywords. Studies were included if they were in English, provided any definition of recovery and were longitudinal. Excluded articles were duplicated studies, case studies, review articles or articles related to alcohol, children, subsyndromal delirium only or those investigating core symptoms such as function.
  
  
  RESULTS
  Fifty-six studies met the inclusion criteria. Only two studies used clinical criteria alone for the diagnosis of delirium; most studies used at least one validated scale-either categorical or continuous severity scales. A variety of 16 different terms were used to define the 'recovery of delirium'. The definitions of each term also varied. Studies using severity scales used either cut-off points or percentage reduction between assessments, while others using dichotomous scales (yes/no) defined recovery as one or more days of negative delirium.
  
  
  CONCLUSIONS
  An agreed terminology to define recovery in delirium is required. A distinction should also be made between symptomatic and overall recovery, as well as between long- and short-term outcomes. It is proposed that cognitive recovery should be central to defining recovery in delirium.
authors.affiliation: Research and Academic Institute of Athens, Athens, Greece Department of Psychiatry, Sligo Mental Health Services, Sligo, Ireland.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Adamis
authors.affiliation: Department of Psychiatry, Sligo Mental Health Services, Sligo, Ireland.
authors.forename: Amanda
authors.initials: A
authors.lastname: Devaney
authors.affiliation: Department of Elderly Medicine, University Hospital Limerick, Limerick, Ireland.
authors.forename: Elaine
authors.initials: E
authors.lastname: Shanahan
authors.affiliation: Department of Psychiatry, Sligo Mental Health Services, Sligo, Ireland Sligo Medical Academy, National University of Ireland, Galway, Sligo, Ireland.
authors.forename: Geraldine
authors.initials: G
authors.lastname: McCarthy
authors.affiliation: Department of Psychiatry, Medical School, University of Limerick, Limerick, Ireland.
authors.forename: David
authors.initials: D
authors.lastname: Meagher
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D003071:Cognition; D032921:Consensus; D003693:Delirium / Q000145:classification* / Q000175:diagnosis* / Q000503:physiopathology / Q000523:psychology / Q000628:therapy; D006801:Humans; D008875:Middle Aged; D020127:Recovery of Function; D012074:Remission Induction; D009626:Terminology as Topic; D013997:Time Factors; D016896:Treatment Outcome
keywords: delirium; older people; outcome; recovery; remission; response