Table 1.
Definitions used and covariates reported in studies of cognitive impairment after ICU discharge
| Study Dates | Study Design Population | Cognitive Test(s) | Definition of abnormality | Quality of outcome measured | Covariates reported in Table 1 |
|---|---|---|---|---|---|
| Ambrosino 2002 [31] January 1996 –December 1998 | Prospective; controlled; consecutive 63 COPD patients requiring MV; control group 34 stable COPD patient on LT oxygen therapy admitted to inpatient pulmonary rehabilitation program | Mini Mental Status Exam (MMSE) | MMSE < 24 | 2 (screening test) | Sex, age, BMI, PFTs, MIP/MEPs, PaCO2/PaO2 |
| Baumbach 2016 [32] September 2014 – March 2015 | Prospective cohort; self-selected by response to contact via mail 127 patients aged 18 to 85 years; mixed MSICU with minimum ICU LOS of 24 hrs | Functional Assessment of Cancer Therapy-Cognitive Function Adapted (FACT-Cogadapted) Informant Questionnaire of Cognitive Decline in the Elderly (IQCODE) | Likert scale; no clear definition of CI | 1 (self-reported) | Sex, age, education, employed (yes/no), APACHEII, hospital LOS, ICU LOS, days of MV, admission diagnosis |
| Bruck 2018 [33] January 2012 – February 2013 | Prospective cohort; patients with sepsis who were part of the PRE-DELIRIC study who responded to questionnaire 125 patients; mixed MSICU with minimum ICU LOS of 24 hrs | Cognitive Failures Questionnaire (CFQ) | Total CFQ score > 25 | 2 | Sex, age, history of cognitive impairment, alcohol use, drug use, diabetes, vascular disease, cardiac disease, APACHEII, type of ICU admission |
| Calsavara 2018 [34]-- | Prospective cohort; severe sepsis or septic shock during ICU stay 33 patients; 16 patients at 1 year | Consortium to Establish Registry for Alzheimer’s Disease (CERAD) battery | -- | 3 (Neuropsychological testing) | Sex, age, education, APACHEII, SOFA, ICU LOS, lab parameters (hemoglobin, Cr, lactate, CRP, glucose), site of infection, comorbidity index, IQCODE, cumulative doses of analgesia/sedatives/inotropes/pressors, steroid exposure, dialysis, days of MV |
| Christie 2006 [35]-- | 2 cross-sectional studies 1) 79 ARDS patients; internet ARDS support site 2) 34 ARDS patients discharged [in-person cognitive interviews] |
Neurobehavioral Cognitive Status Exam (NCSE): Judgment Wechsler Memory Scale )WMS)-III: Digit Span; Letter-Number Sequencing; Logical Memory I/II; Similarities Controlled Oral Word Association Hayling Sentence Completion Test | 2 test scores ≥1 SD or more below the population norm or a single test score ≥1.5 SDs below population norm | 3 | Sex, age, education, race, marital status, alcohol use, smoking status, comorbid conditions, prehospitalization function, prehospitalization cognition, prehospitalization depression |
| Chung 2017 [36] June 2014 – May 2015 | Retrospective; consecutive 30 patients from MICU, CCU and SICU | Mini-Cog test | Recall of 0 items or recall of 1–2 items with an abnormal clock face | 2 | Sex, age, high school graduate (yes/no), type of ICU, reason for admission, GCS at admission, SOFA, days of MV, days delirious, ICU LOS |
| Davydow 2013 [37] September 2010 – August 2011 | Prospective cohort; consecutive 150 nontrauma patients without cognitive impairment or dementia diagnosis who were admitted to an ICU for > 24 hrs; 120 patients completed FU |
Telephone Interview for Cognitive Status modified (TICSm) Mini International Neuropsychiatric Interview |
-- | 2 | Sex, age, education, |
| De Azevedo 2017 [38] March 2014 – February 2015 | Prospective cohort; consecutive 413 adult patients mechanically ventilated | Digit span forward and backward Rey Auditory Verbal Learning Test (RAVLT) Clock-drawing test Verbal fluency test MMSE | Mild or moderate impairment if 2 test scores 1.5 SDs below the mean or test scores 2 SDs below the mean; severe CI if ≥3 test scores 1.5 SD below the mean | 3 | Sex, age, education, APACHE IV, SOFA, days of MV, use of sedative agents, admission diagnosis, delirium (yes/no), ICU LOS |
| De Oliveira 2014 [39] February 2001 – March 2009 | Prospective cohort; consecutive 234 patients with severe TBI (GCS > or = 8); 46 were evaluated at 1 year | WMS-III Logical Memory First Recall; Logical Memory I/II; Visual Reproduction I/II/ III RVALT Total; Retention; Delayed Memory Wechsler Adult Intelligence Scale (WAIS)-III-Digit Span; Vocabulary; Similarities; Block Design; Letters Fluency; Category Fluency | -- | 3 | Sex, age, education, hand dominance, glucose, CT head characteristics, SAH (yes/no), multisystem trauma (yes/no), type of trauma, GCS, pupils |
| De Rooij 2008 [40] January 1997 – December 2002 | Retrospective; consecutive 164 patients >80 yrs; mixed MSICU who underwent elective surgery | IQCODE-SF Katz Activities of Daily Living(ADLs) EQ-5D | Score > 3.9 on IQCODE-SF severe CI; 3.1–3.8 mild-moderate CI | 2 | Sex, age, education, social status, cardiopulmonary resuscitation, GCS after 24 hrs, SAPS II, APACHE II, planned or unplanned admission, BMI, MV (%), ICU LOS |
| Duggan 2017 [41]-- | Prospective; consecutive 826 patients mixed MSICU population for respiratory failure, cardiogenic shock, or septic shock | Behavior Rating Inventory of Executive Function–Adult (BRIEF-A) Trail Making Test B Beck’s Depression Index (BDI)-II Short Form(SF)-36 ADLs Instrumental ADLs (IADLs) | BRIEF-A impairment defined as t-score ≥ 65; Trails B impairment is defined as t-score ≤ 35 | 3 | Sex, age, race, marital status, employment status, baseline clinical status, pre-existing CI, history of depression, history of nondepressive mental illness, comorbidity index, admit diagnosis, ICU type, SOFA, days of MV, septic (yes/no), stroke in hospital (yes/no), ICU LOS, discharge destination |
| Duning 2010 [42] January 2004 – December 2007 | Case-control 74 patients 18–80 yrs of age; 37 patients had at least one hypoglycemic event during SICU admission | MMSE Boston Naming Test Nuernberg Gerontopsychological Inventory Digit symbol substitution Color word interference tasks WMS (revised) Regensburg Word Fluency Test Trail Making test Rey-Osterrieth Complex FigureRAVLT Recognition | -- | 3 (compared to 2) | Matching criteria: sex, age, SAPS II, yr of ICU treatment; disease related criteria: type of OR, CP resuscitation, DM I or II, ICU LOS, mean am blood glucose, duration of sedation (<3 days, 3–7 days, 1–2 weeks, > 2 weeks), PF ratio, CV failure (pressors, MV assist device), renal failure, hepatic failure, medications (steroids, immunosuppressants) |
| Ehlenbach 2010 [43] 1994 – 1996 (2581 participants); 2000 – 2002 (additional 811 individuals) | Prospective; cohort Enrolled patients are evaluated q2yrs; 41 persons were hospitalized for critical illness | Cognitive Abilities Screening Instrument (CASI) | <86 prompted a full standardized clinical exam | 2 | Sex, age, race, education, CAD (yes/no), CV disease (yes/no), pulm dz (yes/no), D< (yes/no), renal dz, malignancy, follow-up time, study visits |
| Girard 2010 [44] October 2003 – March 2006 | Nested in RCT; prospective 76 MICU patients | MMSE Digit span Trail Making tests A and B Digit Symbol Coding Rey-Osterrieth Complex Figure RVALT | 2 cognitive test scores 1.5 SDs below the mean; one cognitive test score 2 SDs below the mean | 3 | Sex, age, education, APACHE II, admission diagnoses (sepsis, ARDS, MI/CHF, COPD/asthma, altered MS, hepatic or renal failure, malignancy, alcohol withdrawal, other), delirium in ICU (prevalence, duration), sedation exposure (benzos, opiates, propofol) |
| Girard 2018 [45] March 2007 - May 2010 | Multicenter; prospective; cohort 586 patients managed in a medical or surgical ICU with respiratory failure, septic or cardiogenic shock, or both | RBANS MMSE Trail Making Test B IQCODE | -- | 3 | Sex, age, race, education, short IQCODE, pre-existing CI, comorbidity index, admission diagnosis, APACHEII, SOFA, days of MV, dexamethasone/benzodiazepine/opioid/ propofol exposure, ICU LOS, hospital LOS, Framingham stroke risk profile, duration of severe sepsis, no. of 15 mins intervals with hypoxia |
| Godbolt 2012 [46] January 2010 – June 2011 | Multicenter; prospective; cohort 110 patients with severe TBI | Barrow Neurological Institute Screening of Cognitive function | Total score < 2 SD below the mean | 2 | -- |
| Guillamondegui 2011 [47] July 2006 – June 2007 | Prospective; cohort 108 patients with moderate-severe TBI; patients with hypoxemic event (SaO2 < 85%) within first 48 hrs of admission | Employment questions and battery of validated neuropsychological testing instruments | 2 test scores 1.5 SDs below the mean or 1 test score 2 SDs below the mean | 3 | Sex, age, ISS, ED GCS, ED pulse, ED SBP, transfusion, MV days, ICU LOS, SpO2 < 90% or 85% for > 5 mins; delirium (prevalence) |
| Hope 2013 [48] January 2003 - December 2007 | Prospective; consecutive; cohort 385 adults admitted to a respiratory care unit for treatment of chronic critical illness; undergone elective tracheostomy for weaning | Validated telephone version of the Confusion Assessment Method (CAM) | Three possible values: dead, alive with brain dysfunction, and alive without brain dysfunction | 2 | Sex, age, race, cognitive impairment at baseline, residence prior to hospitalization, FIM at admission, IADLs at admission, admission diagnosis, type of ICU, ICU LOS, APACHE II, APS, comorbidity index |
| Hopkins 1999 [49] February 1994 – July 1988 | Prospective; consecutive; cohort 67 ARDS survivors | WAIS-R WMS-R RAVLT Rey-Osterrieth Complex Figure Trail Making Tests A and B Verbal Fluency (verbal production) | 2 test scores > 1.5 SD or 1 test score > 2 SD below the normative population mean | 3 | Sex, age, education, ICU LOS, duration MV |
| Hopkins 2004 [50]-- | Prospective; consecutive; cohort 66 ARDS survivors | WAIS-R WMS-R RAVLT Rey-Osterrieth Complex Figure Trail Making Tests A and B Verbal Fluency (verbal production) | <80%, <85% or <90% (compared to normative data) | 3 | Sex, age, education, hospital LOS, ICU LOS, duration MV, APACHE II, mean MOF score, PF ratio, PaO2 at time of enrolment, mean PaO2, FiO2 at time of enrolment, days from ARDS onset to enrolment in 1 yr outcome study |
| Hopkins 2005 [51] February 1994 – December 1999 | Prospective; consecutive; cohort 66 ARDS survivors (low vs. high tidal volume ventilation study) | WAIS-R WMS-R RAVLT Rey-Osterrieth Complex Figure Trail Making Tests A and B Verbal Fluency (verbal production) | 2 or more test scores > 1.5 SDs or 1 test score > 2 SDs below normative population mean | 3 | Sex, age, education, race, number of ARDS RFs, duration MV, ICU LOS, hospital LOS, at study enrolment (APACHE II, MOF score, PF ratio, FiO2, PaO2); total ICU stay (mean MOF score, mean PF ratio, Mean FiO2, mean PaO2) |
| Hopkins 2005 [52]-- | Prospective; cohort 32 patients having received >5 days of MV | Neuropsychological testing-- | ≥2 test scores > 1.5 SDs or 1 test score > 2 SD below normative population mean | 3 | Sex, age, education, Charlson comorbidity index, number of ARDS RFs, duration MV, ICU LOS, hospital LOS, at study enrolment (APACHE II, MOF score, PF ratio, FiO2, PaO2); total ICU stay (mean MOF score, mean PF ratio, Mean FiO2, hrs oximetry SaO2 < 90%, hrs MBP < 60 mmHg, hrs MBP < 50 mmHg, days reciving either sedatives, narcotics or paralytics) |
| Hopkins 2010 [53] February 1994 – December 1999 | Prospective; consecutive; cohort 66 ARDS survivors (low vs. high tidal volume ventilation study) | WAIS-R WMS-R RAVLT Rey-Osterrieth Complex Figure Trail Making Tests A and B Verbal Fluency (verbal production) | 2 or more test scores > 1.5 SD or 1 test score > 2 SD below normative population mean using age, gender and education corrected t-scores | 3 | Sex, age, education, hospital LOS, DM I or II, total corticosteroid dose, at study enrolment (APACHE II, MOF score, PF ratio, FiO2, PaO2); total ICU stay (duration MV, ICU LOS, Mean FiO2, mean PaO2, hrs oximetry SaO2 < 90%, total insulin units/ICU hours, total potassium dose, mean blood glucose, lowest glucose, highest glucose) |
| Hughes 2017 [54] March 2007 - May 2010 | Multicentre; prospective; cohort 1040 patients with major noncardiac surgery during hospital admission and with nonsurgical medical illness | RBANS Trail Making Test B | -- | 3 | Sex, age, race, education, SES, IQCODE, clinical frailty score, functional activities questionnaire, comorbidity index, Framingham stroke risk profile, SOFA< APACHE II, sepsis in ICU, days of MV, ever delirious, coma, sedative or analgesia use, ICU LOS, hospital LOS |
| Hughes 2018 [55] | Multicentre; prospective; cohort 419 adults admitted to a MICU or SICU with respiratory failure and/or shock | RBANS Trail Making Test B Katz ADLs Functional activities questionnaire | -- | 3 | Sex, age, race, education, SES, IQCODE, clinical frailty score, functional activities questionnaire, comorbidity index, Framingham stroke risk profile, SOFA< APACHE II, sepsis in ICU, days of MV, ever delirious, coma, sedative or analgesia use, ICU LOS, hospital LOS |
| Iwashyna 2010 [56] 1998 – 2006 | Prospective; nonconsecutive; cohort Enrolled patients are evaluated q2yrs; survivors of severe sepsis | 35-point scale; tests of memory, serial 7 subtractions, naming and orientation ADLs IADLs | -- | 2 | Sex, age, education, race, LOS, required MV, required dialysis, used ICU, underwent major surgery, Charlson score, organ dysfunction score, acute conditions (CV dysfunction, neurologic dysfunction, hematologic dysfunction, hepatic dysfunction, renal/respiratory dysfunction), baseline cognitive impairment, baseline functional disability |
| Jackson 2003 [57] February 2000 – May 2001 | Prospective; cohort; consecutive 34 patients; MICU and CICU; requiring MV | Modified Blessed Dementia Rating Scale (mBDRS) MMSE Digit Symbol Coding Thurstone Word Fluency Letter Number Sequencing Sequencing Verbal Paired Associates Digit Symbol Paired Recall Recall (Faces) Rey-Osterrieth Complex Figure | 2 test scores > 2 SDs below the norm-referenced mean or 3 test scores ≥1.5 SD below norm-referenced mean | 3 | Sex, age, education, race, ADL, APACHE, Charlson, SOFA, Admission diagnosis |
| Jackson 2007 [58] January 2003 – December 2003 | Prospective; nonconsecutive; cohort 58 trauma patients without ICH or focal neurologic deficits or moderate to severe TBI | Digit span Digit symbol FAS IQCODE-SF MMSE RAVLT Rey-Osterrieth Complex Figure Trail Making Tests A and B Katz ADLs | ≥2 test scores > 1.5 SDs or 1 test score > 2 SDs below normative population | 3 (compared to 2) | Sex, age, education, race, ISS, type of trauma, mental health history, employment status |
| Jackson 2010 [22] October 2003 – March 2006 | Randomised controlled trial of SAT/SBT 80 patients requiring MV for > 72 hrs | Digit span Digit symbol IQCODE-SF MMSE RAVLT Rey-Osterrieth Complex Figure Trail Making Tests A and B Verbal Fluency test Katz ADLs | ≥1.5 SDs below the mean on ≥2 of the nine cognitive tests or scored ≥2 SDs below the mean on ≥1 of the nine cognitive tests | 3 | Sex, age, APACHE II, SOFA, Admission diagnosis, pre-existing cognitive impairment, baseline ADL, baseline IADL, pre-enrolment sedative exposure, sedative exposure, lorazepam equivalents, fentanyl equivalents, propofol |
| Jackson 2011 [59] July 2006 – June 2007 | Prospective; cohort 108 patients with moderate to severe trauma; no ICH | Digit span Digit symbol Verbal Fluency test (FAS) IQCODE-SF MMSE RAVLT Rey-Osterrieth Complex Figure Trail Making tests A and B | ≥2 test scores > 1.5 SDs or 1 test score > 2 SDs below normative population | 3 | Sex, age, education, race, ISS, admission GCS, long-bone fracture, concussion, ICU LOS, hospital LOS, MV status, duration of MV, CAM+ days, type of trauma |
| Juan 2018 [60] July 2012 - May 2015 | Prospective; cohort 50 survivors included from a prospective cohort of 138 patients admitted at the ICU for cardiopulmonary arrest | Naming subtest of the Lexis battery California Verbal Learning Test Doors and People test Digit span forward subtest of WAIS-IV Block tapping WMS-R Five-points test Digit-symbol subtest of the WAIS-IV Alert and Divided attention subtests of the Test battery Trail Making and Stroop tests from the GREFEX battery | z score less than or equal to –1.65 SDs of the mean | 3 | Sex, age, cardiac etiology arrest, out of hospital cardiac arrest, time to return of spontaneous circulation, first shockable rhythm, therapeutic hypothermia (yes/no) |
| Jones 2006 [61] March 2003 – November 2004 | Prospective; cohort 30 long-stay, MV patients | Cambridge Neuropsychological Test Automated Battery (CANTAB) | ≤25 percentile compared with an age-, sex-matched control population | 3 | Sex, age, APACHE II, ICU LOS, diagnostic groups (peritonitis, pneumonia, asthma/COPD, sepsis, ARDS, trauma) |
| Larson 2007 [62] February 1994 – December 1999 | Interventional trial; higher vs lower tidal volume ventilation strategy 66 ARDS survivors | WAIS-R (FSIQ; Vocabulary; Block Design) WMS-R (Attention Index; Verbal; RAVLT; Visual; Rey-Osterrieth Complex Figure) Trail Making Test B | ≥2 test scores > 1.5 SDs or 1 test score > 2 SDs below normative population mean values using age, gender and education | 3 | Sex, age, hospital LOS, ICU LOS, duration of MV, APACHE II, Charlson Comorbidity index, mean MOF score, mean PaO2, mean FiO2, PF ratio, days receiving sedatives/narcotics/paralytics |
| Lippert-Gruner 2006 [63] | Prospective; cohort 41 patients with severe TBI | Neurobehavioural Rating Scale | -- | 2 | Sex, age |
| Maley 2016 [64] January – May 2014 | Prospective; mixed-methods investigation 43 survivors from two MICUs | Health Utilities Index - 3 cognitive questions Hospital Anxiety and Depression Scale (HADS) Connor-Davidson Resilience Scale Life-Space Questionnaire | -- | 1 | Sex, age, race, marital status, no. of hospitalization in prior yr, comorbidity score, days of MV, sepsis LOS, shock LOS, ICU LOS, hospital LOS, disposition destination |
| Marquis 2000 [65] | Prospective; parallel controlled cohort 33 ARDS survivors; 24 critically ill controls | Trail Making Test B Symbol Digit Modalities test Test of Everyday Attention (Elevator Counting with Distraction) | -- | 3 | -- |
| Mikkelsen 2009 [66] | Cross-sectional 79 self-reported ARDS survivors | NCSE (Orientation, Judgment) WMS-III (Digit Span, Letter – Number Sequencing, Logical Memory, Similarities) Hayling Sentence Completion Test Controlled Oral Word Association Test | ≥2 test scores > 1 SD or 1 test score > 1.5 SDs below normative population | 3 | Sex, age, education, employment status, hospital LOS, precipitating factors (pneumonia, surgery, sepsis, trauma, other) |
| Mikkelsen 2012 [67] June 2000 – October 2005 | Prospective; multicenter; cohort 75 ALI survivors | Neuropsychological test battery (45–60 minutes); nil other specifics reported | 1 test score > 2 SDs below normative population | 3 | Sex, age, race, primary lung injury, coexisting conditions (none, DM, HIV/AIDS, cirrhosis, solid tumor, leukemia, lymphoma, immunosuppression), APACHE III, GCS, MAP, vasopressor use, PF ratio, conservative fluid strategy, PAC |
| Mitchell 2016 [68] November 2011 – December 2014 | Prospective; cohort 148 adult surgical, medical and trauma patients enrolled; 88 tested at 3-months and 79 tested at 6-months | RBANS Trail Making Test Part B MMSE | Classified as severely impaired if they scored 1.5 SDs below the mean on ≥3 of the index scores or 2 SDs below the mean on ≥2 of the index scores | 3 | Sex, age, education, admission diagnosis, APACHE II, APACHE III, ICU LOS, hospital LOS, Propofol/benzodiazepine/opioid dose, days of MV, delirium in ICU days |
| Needham 2013 [19] July 2008 – May 2012 | Multicentre; prospective; cohort 174 patients | Controlled oral word association (COWA) Digit span Hayling sentence completion Logical memory I/II Similarities | <1.5 SDs on any of tests | 3 | Sex, age, race, high school education (yes/no), BMI, steroids (yes/no), living independently at home prior to admission (yes/no), employed (yes/no), SF-36, functional performance inventory score, comorbidity score, comorbidities at admission, critical illness characteristics (pneumonia, sepsis, baseline shock, baseline PF ratio, APACHE II, days of MV, hypoglycemia, steroids, insulin, benzodiazepines, NMBs, narcotics, ever coma, ever delirious, ICU LOS, hospital LOS) |
| Pandharipande 2013 [7] March 2007 – May 2010 | Multicentre; prospective 467 adults admitted to a medical or surgical ICU with respiratory failure, cardiogenic shock, or septic shock | RBANS Trail Making Test B | 1.5 and 2 SDs below the population means | 3 | Sex, age, race, ICU type, education, short IQCODE, comorbidity score, APACHE II, SOFA, admission diagnosis, days of MV, days delirious, coma (yes/no), hospital LOS, use of sedatives/analgesia in ICU |
| Pasternak 2008 [69] February 2000 – April 2003 | Posthoc analysis of data from Intraoperative Hypothermia for Aneurysm Surgery Trial 878 patients with SAH; underwent aneurysm surgery | Benton Visual Retention test Controlled Oral Word Association Rey-Osterrieth Complex Figure Test Grooved Pegboard test Trail Making test Glasgow Outcome Score (GOS) | 1 test score > 2 SDs below normative population | 3 | Blood glucose at aneurysm clipping, age, sex, race, BMI, preoperative hx (DM, HTN, smoking, time from SAH to induction), WFNS, Fisher grade, NIHSS, preoperative Rankin score, hydrocephalus on initial CT |
| Pfoh 2015 [70] July 2008 – May 2012 | Cross-sectional secondary analysis of data from two prospective studies of acute respiratory failure patients requiring mechanical ventilation in an ICU | MMSE COWA Logical memory I/II Digit span total score, forward and backward | MMSE conservative cutoff score of <24 | 2 | Sex, age, education, employed, comorbidity score, psychiatric condition, severity illness score, days of MV, ICU LOS, hospital LOS |
| Pierrakos 2017 [71] January 2013 - January 2014 | Prospective; consecutive; cohort 28 patients with sepsis | MMSE IADLs | -- | 2 | Sex, age, APACHE II, IADL, pCO2, MAP, septic shock, days of MV, sedation, relapsing infection (yes/no), delirium (yes/no) |
| Rothenhausler 2001 [72] January 1985 – January 1995 | Prospective; consecutive; cohort 46 ARDS survivors | Short Cognitive Performance test (SKT) | SKT total scores (profound cognitive impairment: 24–27; severe: 19–23, moderate: 14–18, mild: 9–13; subthreshold: 5–8) | 2 | Sex, age, RF for ARDS (trauma, sepsis, pneumonia, other) |
| Sacanella 2011 [73] -- | Prospective; consecutive; Cohort 112 elderly patients electively admitted to MICU | MMSE IQCODE | MMSE < 24 | 2 | Sex, age, APACHE II, SOFA, ICU LOS, cardiac dx, respiratory dx, severe sepsis, CV dx, other medical dx, % MV, % RRT, OMEGA score, Charlson index |
| Sakuramoto 2015 [74] July – December 2009 | Prospective; consecutive; cohort 79 adults admitted to MICU or SICU | MMSE | MMSE < 24 | 2 | Sex, age, comorbidity score, vision deficits, hearing deficits, mBDRS score, APACHE, SOFA, days of MV, ICU LOS, hospital LOS, admission diagnosis |
| Schielke 2005 [75] January 1999 – June 1999 | Prospective; consecutive; cohort 27 patients treated for ischemic stroke requiring MV | MMSE National Institutes of Health Stroke Scale Barthel Index modified Rankin Scale | MMSE < 24 | 2 | -- |
| Semmler 2013 [76] January 2004 – August 2006 | Two center; prospective; non-consecutive; cohort 25 survivors of sepsis; 19 non-septic ICU survivors | Neuro Cognitive Effects (NeuroCogFx) Trail Making tests A and B Auditory Verbal Learning Test Rey-Osterrieth Complex Figure Test | > 1.5 SD from z differences scores | 3 | Age, estimate premorbid verbal ability, APACHE II, SOFA, ICU LOS, duration MV, electrolyte levels (Na and K), PF ratio (max), creatinine (max), HCT (max), MAP < 70 mmHg, ARDS %, surgery (emergent or elective), admission diagnosis, comorbid medical disorders (cardiac, respiratory, live, DM, immunosuppressed, cancer, renal dx, CV dx, GI dx, multiple disorders), drugs (sedatives, analgesics, vasopressor, other drug) |
| Suchyta 2004 [77] | Prospective; cohort 30 ARDS patients | -- | ≥2 test scores that were > 1 SD for mild, >1.5 SDs for moderate or ≥2 SDs for severe cognitive impairment | 3 | Sex, age, education, APACHE II, hospital LOS, PF ratio, RF for ARDS |
| Suchyta 2010 [78] July 2003 – June 2004 | Prospective; non-consecutive; cohort 46 MSICU patients | -- | -- | -- | Duration MV, ICU LOS, hospital LOS, APACHE II at ICU admission, % ARDS, admission diagnosis, co-morbid dx (cardiac, respiratory, liver, DM, immunosuppressed, cancer, renal dx, CV dx, GI dx, multiple disorders); hrs SpO2 < 90%, hrs MAP < 60 mmHg, sedatives (total dose ICU admission to scan) including lorazepam/fentanyl/morphine/midazolam/ propofol/hydromorphone, steroids |
| Sukantarat 2005 [79] April 2000 – March 2003 | Prospective; consecutive; cohort 51 MSICU patients | Hayling Sentence Completion test Modified Six Element test Raven’s Standard Progressive Matrices | Compared to percentiles of population norms | 3 | Sex, age, LOS, duration MV, APACHE II, TISS points |
| Teeters 2011 [80] 2004 – 2008 | Prospective; cohort 387 elderly patients admitted to ICU | Clinical Dementia Rating Scale FAQ Neurologic evaluation Neuropsychiatric testing | Expert consensus | 3 | Sex, age, APACHE III |
| Tembo 2012 [81] -- | Qualitative 12 MSICU patients | Face-to-face interviews | Self-reported | 2 | -- |
| Tobar 2009 [82] September 2008 – April 2009 | Prospective; cohort 8 MICU patients | MMSE MOCA | MMSE < 21 (norm for Chile) | 2 | Sex, age, APACHE II, SOFA, delirium days, duration MV, hospital LOS |
| Torgersen 2011 [83] January 2008 – February 2009 | Prospective; consecutive; cohort (parallel surgical cohort; not requiring ICU admission) 28 SICU patients; 24 surgical patients | CANTAB MMSE DMS (delayed matching to sample) Stocking of Cambridge Paired associate learning test SF-36 | MMSE < 24 Z-score below −2 SD on 2 or below 1.5 SDs on 3 out of 10 results reported by CANTAB | 3 | Sex, age, ICU LOS, duration MV, SAPS II, mac SOFA score, Charlson comorbidity index |
| Vitaz 2003 [84] October 1995 – March 1998 | Prospective; consecutive; cohort 56 patients with moderate TBI | Telephone interview; questions regarding ADLs and mental functioning | Self-report | 1 | Age, median 24-hr GCS, hospital LOS, ICU LOS, duration MV |
| Wolters 2017 [85] January 2011 – June 2013 | Prospective; consecutive; cohort 363 adult patients in mixed MSICU for > 48 hrs | Cognitive Failures Questionnaire (CFQ) | -- | 1 | Sex, age, comorbidity index, APACHE IV, SOFA, ICU LOS, admission type |
| Woon 2012 [86] August 2007 – December 2008 | Prospective; consecutive; cohort 53 patients MSICU | MMSE Mini-Cog WASI (full-scale, verbal, performance) Trail Making tests A and B Hayling Sentence Completion Test WASI-R (digit symbol) WMS-III (logical memory) California Verbal Learning Test-II Rey-Osterrieth Complex Figure Test Finger Tapping test Controlled Oral Word Association test Wide-Range Assessment test-3 (reading) Golden Stroop test (inference trial) | MMSE < 24 MiniCog considered impaired if recalled no words, or recalled 1 or 2 words with an abnormal clock drawing score NP testing: ≥2 or test scores > 1.5 SDs or 1 test score that was > 2 SDs below population norms | 3 | Sex, age, education, ICU LOS, hospital LOS, duration MV, max FiO2, Min PaO2, APACHE II, ICU admission diagnosis |
| Zhao 2017 [87] January 2013 to September 2013 | RCT 332 patients; 165 patients were included in the control group and 167 in the cognitive intervention group | Montreal Cognitive Assessment (MoCA) | < 26 was considered CI | 2 | Sex, age, education, ICU LOS, ICU type, comorbidity index, medications (steroids, analgesia, sedation) |
ARDS: acute respiratory distress syndrome; ALI: acute lung injury; COPD: chronic obstructive pulmonary disease; LT: long-term; MV: mechanical ventilation; LOS: length of stay; ICU: intensive care unit; MSICU: medical-surgical ICU; CCU: coronary care unit; SICU: surgical ICU; CICU: cardiac ICU; FU: follow-up; TBI: traumatic brain injury; GCS: Glasgow coma score; RCT: randomized controlled trial; SAT: spontaneous awakening trial; SBT: spontaneous breathing trial; ICH: intracerebral hemorrhage; SAH: subarachnoid hemorrhage