Table 1

Displays the 27 studies that were identified for inclusion in this review.

AuthorStudy design population sample size sampling method power analysisStudy grade (NOS)Outcome variable and rate (%)Delirium measurement and frequencyDPM name and regression model used
 Carrasco et al 23 P.Cohort
Medical
Dev: 374
Val: 104
Consecutive
S: ****
C: –
O: **
T: 6 stars
Delirium
Dev: 25 (0.06)
Val: 12 (12)
CAM
Every 48 hours
Predictive Risk Score
Forward stepwise
de Wit et al 24 Retro
All hospital patients
Dev: 1291
Convenience
Power analysis
S: ***
C: **
O: ***
T: 8 stars
Delirium
Dev: 225 (17)
Chart abstraction EHR ‘diagnosis table’Automated delirium prediction model
Multivariate
Douglas et al*25 P.Cohort
Medical
Dev: 209
Val: 165
Consecutive
Power analysis
S: ****
C: –
O: ***
T: 7 stars
Delirium
Dev: 25 (12)
Val: 14 (8.5)
 Short CAM
Daily
Risk stratification model (AWOL)
Forward stepwise
Dworkin et al 47 P.Cohort
Elective non-cardiac surg
Dev: 76
Consecutive
S: ****
C: –
O: **
T: 6 stars
Delirium
Dev: 10 (13)
CAM or
FAM-CAM
1× after surgery
Mini-Cog
Stratified into a five-point score
Stepwise
Fisher and Flowerdew26 P.Cohort
Elective orthopaedic
Dev: 80
Consecutive
S: **
C: −
O: **
T: 4 stars
Delirium
Dev: 14 (17.5)
CAM
2× Daily
Prediction model using two variables.
 Stepwise
Freter et al 28 P.Cohort
Elective hip surgery
Dev: 132
Consecutive
S: **
C: **
O: **
T: 6 stars
Delirium
Dev: 18 (14)
CAM
Daily
Risk stratification model (DEAR)
Built from literature
Freter et al 49 P.Cohort
Hip Fx
Dev: 100
Consecutive
S: **
C: **
O: **
T: 6 stars
Delirium
Dev: 24 (24)
CAM
Daily
Risk stratification model (DEAR)
Freter et a 27 P.Cohort
Hip fracture
Val: 283
Consecutive
S: ***
C: –
O: **
T: 5 stars
Delirium
Val: 119 (42)
CAM
POD1, 3 and 5
Risk stratification model (DEAR)
Inouye and Charpentier29 P.Cohort
Medical
Dev: 196
Val: 312
Consecutive
S: ****
C: **
O: ***
T: 9 stars
Delirium
Dev: 35 (18)
Val: 47 (15)
CAM
Every other day
Risk stratification model based on precipitating factors
Backwards and forwards stepwise
Inouye et al 31 P.Cohort
Medical
Dev: 491
Val: 461
Consecutive
S: ****
C: **
O: ***
T: 9 stars
Delirium/subsyndrome delirium at discharge
Dev: 58 (12)
Val: 28 (6)
CAM
Every other day
Risk stratification model
Log-binomial regression
Inouye et al 30 P.Cohort
Medical
Dev: 107
Val: 174
Consecutive
S: ****
C: **
O: ***
T: 9 stars
Delirium
Dev: 27 (25)
Val: 29 (17)
CAM
Daily
Risk stratification model
Forward stepwise
Isfandiaty et al 32 Retro
Medical
Dev: 457
Convenience
S: **
C: –
O: ***
T: 5 stars
Delirium
Dev: 87 (19)
Undefined
Daily
Risk stratification model
Cox’s proportional hazard
Kalisvaart et al 34 P.Cohort
Hip surgery and fracture
Val: 603
Consecutive
S: ***
C: –
O: ***
T: 6 stars
Delirium
Val: 74 (12)
CAM, DRS-98
Daily through POD5
Externally validated Inouye’s 1993 model.
Kim et al 35 P.Cohort
Major general surgery
Dev: 561
Val: 533
Not stated
Power analysis
S: ***
C: **
O: ***
T: 8 stars
Delirium
Dev: 112 (20)
Val: 99 (18)
Nu-Desc: 
every shift by RNs
Confirmed with CAM
Risk stratification model
Backwards stepwise
Korc-Grodzicki et al 36 Retro
Oncological surgery
Dev: 416
Convenience
S: ***
C: –
O: ***
T: 6 stars
Delirium
Dev: 79 (19)
CAM
Daily
Comprehensive Geriatric Assessment (CGA) as model
Stepwise
Leung et al 37 P.Cohort
Non-cardiac surgery
Dev: 581
Not stated
S: ***
C: –
O: **
T: 5 stars
Delirium
Dev: 234 (40)
CAM
Daily
Risk stratification model
Stepwise
Liang et al 38 P.Cohort
Elective orthopaedic Surgery
Dev: 461
Consecutive
S: ***
C: **
O: **
T: 7 stars
Delirium
Dev: 37 (8)
CAM
Daily
Confirmed by psychologist
DSM-IV
Built two DPMs using
CGA
Risk stratification models
Backward stepwise
Maekawa et al 39 P.Cohort
Oncological; gastrointestinal surgery
Dev: 517
Consecutive
S: **
C: *
O: ***
T: 6 stars
Delirium
Dev: 124 (24)
CAM
Unknown frequency
CGA as model
Proportional hazards
Martinez et al 40*P.Cohort
Medical
Dev: 397
Val: 302
Consecutive
Power analysis
S: ***
C: –
O: **
T: 5 stars
Delirium
Dev: 52 (13)
Val: 76 (25)
CAM
Undefined
Clinical prediction rule
Multivariate
Recursive partitioning
Moerman et al 41 P.Cohort
Hip fracture
Val: 378
Consecutive
Power analysis
S: ***
C:–
O: ***
T: 6 stars
Delirium
Val: 102 (27)
Ward RN observation, 3× daily
Confirmed by chart review
Risk stratification model (Risk Model for Delirium, RD)
Built from literature
O’Keeffe and Lavan42 P.Cohort
Acute geriatric unit
Dev: 100
Ival: 84
Consecutive
S: ****
C: –
O: **
T: 6 stars
Delirium
Dev: 28 (28)
IVal: 25 (30)
DAS
Every 48 hours
DSM III
Risk stratification model
Stepwise
Pendlebury et al 48 P.Cohort
Medical
Val: 308
Consecutive
S: ****
C: **
O: ***
T: 9 stars
Delirium
Val: 95 (31)
CAM
Every 48 hours
Confirmed by DSM-IV interview
Susceptibility Score
Built from literature
Pendlebury et al 33 P.Cohort
Medical
Val: 308
Consecutive
Power analysis
S: ****
C: –
O: ***
T: 7 stars
Delirium
Val: 95 (31)
CAM
Every 48 hours
Confirmed by DSM-IV interview
Externally validated four DPMs
Pompei et al 43 P.Cohort
Med/surg
Dev: 432
Val: 323
Not stated
S: ****
C: **
O: ***
T: 9 stars
Delirium
Dev: 64 (14.8)
Val: 86 (26.3)
CAM
2× weekly.
Confirmed with DSM III
Risk stratification model
Stepwise
Rudolph et al 46 P.Cohort
Cardiac surgery
Dev: 122
Val: 109
Not stated
S: ***
C: *
O: **
T: 6 stars
Delirium
Dev: 63 (52)
Val: 48 (44)
CAM, MDAS, DSI
Daily
Risk stratification model
Backward stepwise
Rudolph et al 45 P.Cohort
Medical
Val: 100
Consecutive
S: ****
C: –
O: ***
T: 7 stars
Delirium
Dev: 23 (23)
DSM-IV
Daily clinical interview
Externally validated Inouye’s 1993 model
Rudolph et al 44 Dev: Retro
Val: P.Cohort
Med/surg
Dev: 27 625
Val: 246
Consecutive
S: ****
C: –
O: **
T: 6 stars
Delirium
Dev: 2343 (8)
Val: 64 (26)
Dev: chart audit
Val: DSM-IV
Daily clinical interview
Risk stratification model
Built from literature
  • Study design: Dev, development; Med, medical; P.Cohort, prospective cohort; Retro, retrospective design; Surg, surgical; Val, validation; Power analysis, reported in identified study. Study grade:  NOS, Newcastle Ottawa Scale; C, comparability;  O, Ottawa; S, Selection; T, Total; Max 9 stars. Outcome variable: CAM, Confusion Assessment Method; DRS-98, Delirium Rating Scale-R-98; DSM, Diagnostic Statistical Manual; EHR, Electronic Health Record; MDAS, Memorial Delirium Assessment Scale; Nu-Desc, Nursing Delirium Screening Scale; POD, postoperative day; DSI, Delirium Symptom Interview; DAS, Delirium Assessment Scale; FAM-CAM, Family Confusion Assessment Method, RNs, Registered Nurses; IVAL, Internal Validation

  • Type of model: how authors designed their delirium prediction model (DPM), statistical method used.

  • Risk stratification model: points (weighted or unweighted) assigned per predictive risk factor present.

  • Built from literature: authors selected risk factors for DPM based on literature review.

  • AWOL, DEAR, and RD are the names of the prediction models given by the developing authors.

  • *Models developed in population ≤60 years of age but validated in population ≥60 years of age.

  • CGA, Comprehensive Geriatric Assessment.