title: A comparison of the revised Delirium Rating Scale (DRS-R98) and the Memorial Delirium Assessment Scale (MDAS) in a palliative care cohort with DSM-IV delirium.
abstract: OBJECTIVE
  Assessment of delirium is performed with a variety of instruments, making comparisons between studies difficult. A conversion rule between commonly used instruments would aid such comparisons. The present study aimed to compare the revised Delirium Rating Scale (DRS-R98) and Memorial Delirium Assessment Scale (MDAS) in a palliative care population and derive conversion rules between the two scales.
  
  
  METHODS
  Both instruments were employed to assess 77 consecutive patients with DSM-IV delirium, and the measures were repeated at three-day intervals. Conversion rules were derived from the data at initial assessment and tested on subsequent data.
  
  
  RESULTS
  There was substantial overall agreement between the two scales [concordance correlation coefficient (CCC) = 0.70 (CI 95 = 0.60-0.78)] and between most common items (weighted κ ranging from 0.63 to 0.86). Although the two scales overlap considerably, there were some subtle differences with only modest agreement between the attention (weighted κ = 0.42) and thought process (weighted κ = 0.61) items. The conversion rule from total MDAS score to DRS-R98 severity scores demonstrated an almost perfect level of agreement (r = 0.86, CCC = 0.86; CI 95 = 0.79-0.91), similar to the conversion rule from DRS-R98 to MDAS.
  
  
  CONCLUSIONS
  Overall, the derived conversion rules demonstrated promising accuracy in this palliative care population, but further testing in other populations is certainly needed.
authors.affiliation: Department of Adult Psychiatry,University Hospital Limerick,Limerick,Ireland.
authors.forename: Roisin
authors.initials: R
authors.lastname: O'Sullivan
authors.affiliation: Department of Adult Psychiatry,University Hospital Limerick,Limerick,Ireland.
authors.forename: David
authors.initials: D
authors.lastname: Meagher
authors.affiliation: Department of Adult Psychiatry,University Hospital Limerick,Limerick,Ireland.
authors.forename: Maeve
authors.initials: M
authors.lastname: Leonard
authors.affiliation: Department of Geriatric Medicine,Oslo University Hospital,Oslo,Norway.
authors.forename: Leiv Otto
authors.initials: LO
authors.lastname: Watne
authors.affiliation: Edinburgh Delirium Research Group,University of Edinburgh,Scotland.
authors.forename: Roanna J
authors.initials: RJ
authors.lastname: Hall
authors.affiliation: Edinburgh Delirium Research Group,University of Edinburgh,Scotland.
authors.forename: Alasdair M J
authors.initials: AM
authors.lastname: Maclullich
authors.affiliation: Lilly Research Laboratories, Indianapolis,Indiana.
authors.forename: Paula
authors.initials: P
authors.lastname: Trzepacz
authors.affiliation: Cognitive Impairment Research Group,University of Limerick Medical School,Limerick,Ireland.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Adamis
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D003693:Delirium / Q000145:classification*; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010166:Palliative Care; D011569:Psychiatric Status Rating Scales / Q000592:standards*
keywords: Assessment; DRS–R98; Delirium; Delirium scales; Equation method; MDAS; Phenomenology