Clinical trials data
Cognitive tests in delirium, surgery and intensive care trials: 619 registered studies
Every registered delirium, surgery and intensive care study on ClinicalTrials.gov that names a cognitive test in an outcome measure: the tests used most, how often as a primary outcome, which tests go together, how large the studies are and when they measure the outcome.
- Registered delirium, surgery and intensive care studies name a cognitive test in an outcome
- 619
- Led by industry
- 9
The tests delirium, surgery and intensive care trials use most
The Trail Making Test leads: 69 of the 619 studies name it, 11%. Next comes Verbal Learning (51). As a primary outcome, the Trail Making Test leads with 34 studies.
- 1
Trail Making Test69 studies, 34 as a primary outcome
- 2
Verbal Learning51 studies, 31 as a primary outcome
- 3
Verbal Fluency46 studies, 20 as a primary outcome
- 4
Digit Span Test44 studies, 20 as a primary outcome
- 5
Stroop Color-Word Test37 studies, 24 as a primary outcome
- 6
Symbol Coding29 studies, 11 as a primary outcome
- 7
Clock Drawing Task20 studies, 6 as a primary outcome
- 8
Category Fluency13 studies, 5 as a primary outcome
- 9
Picture Naming Test10 studies, 3 as a primary outcome
- 10
Short Story Recall9 studies, 5 as a primary outcome
- 11
Complex Figure Copy and Recall7 studies, 5 as a primary outcome
- 12
Remember and Know Test6 studies, 4 as a primary outcome
- 13
Sentence Completion Inhibition Test6 studies, 3 as a primary outcome
- 14
Psychomotor Vigilance Task5 studies, 2 as a primary outcome
- 15
N-Back Task5 studies, 1 as a primary outcome
- 16
Go/No-Go Task4 studies, 2 as a primary outcome
- 17
Continuous Performance Test4 studies, 1 as a primary outcome
- 18
Corsi Block-Tapping Test3 studies, 3 as a primary outcome
- 19
Task Switching Test3 studies, 2 as a primary outcome
- 20
Tower Planning3 studies, 1 as a primary outcome
- 21
Paced Visual Serial Addition Test3 studies, 0 as a primary outcome
- 22
Pattern and Letter Comparison3 studies, 0 as a primary outcome
- 23
Size Order Memory Test3 studies, 0 as a primary outcome
- 24
Choice Reaction Time2 studies, 2 as a primary outcome
- 25
Contrast Sensitivity Test2 studies, 2 as a primary outcome
A test as a primary outcomeOnly in secondary or other outcomes
68% of delirium, surgery and intensive care studies name only instruments outside the library, such as clinician-administered screening scales. They count in every figure on this page and are not listed. The explorer below holds all 57 tests.
Tests used together
- Trail Making Test and Verbal Learning23 studies name both
- Stroop Color-Word Test and Verbal Learning22 studies name both
- Digit Span Test and Trail Making Test21 studies name both
- Verbal Fluency and Verbal Learning20 studies name both
- Trail Making Test and Verbal Fluency19 studies name both
- Digit Span Test and Verbal Fluency17 studies name both
- Digit Span Test and Verbal Learning15 studies name both
- Symbol Coding and Trail Making Test15 studies name both
- Stroop Color-Word Test and Trail Making Test13 studies name both
- Symbol Coding and Verbal Fluency13 studies name both
Studies by start year
A test as a primary outcomeOnly in secondary or other outcomes
Show as a table
| Start year | Studies | A test as a primary outcome |
|---|---|---|
| 2000 | 0 | 0 |
| 2001 | 1 | 1 |
| 2002 | 1 | 0 |
| 2003 | 0 | 0 |
| 2004 | 1 | 1 |
| 2005 | 1 | 1 |
| 2006 | 2 | 2 |
| 2007 | 5 | 1 |
| 2008 | 4 | 3 |
| 2009 | 6 | 4 |
| 2010 | 4 | 1 |
| 2011 | 5 | 2 |
| 2012 | 10 | 3 |
| 2013 | 14 | 6 |
| 2014 | 20 | 12 |
| 2015 | 26 | 13 |
| 2016 | 19 | 9 |
| 2017 | 29 | 11 |
| 2018 | 31 | 7 |
| 2019 | 37 | 15 |
| 2020 | 51 | 20 |
| 2021 | 45 | 16 |
| 2022 | 45 | 14 |
| 2023 | 68 | 18 |
| 2024 | 67 | 26 |
| 2025 | 50 | 17 |
| 2026 | 74 | 31 |
Phases and sponsors
By phase
- Early phase 18 studies, 4 as a primary outcome
- Phase 15 studies, 2 as a primary outcome
- Phase 1/23 studies, 1 as a primary outcome
- Phase 223 studies, 9 as a primary outcome
- Phase 2/35 studies, 1 as a primary outcome
- Phase 324 studies, 6 as a primary outcome
- Phase 462 studies, 20 as a primary outcome
- Not applicable271 studies, 85 as a primary outcome
- Observational218 studies, 106 as a primary outcome
Sponsors and study types
Lead sponsor: industry 9, NIH 0, universities, hospitals and others 610. Interventional 401, observational 218.
Status, results, interventions and countries
Status
- Recruiting113 studies, 32 as a primary outcome
- Not yet recruiting55 studies, 22 as a primary outcome
- Active, not recruiting24 studies, 8 as a primary outcome
- Completed264 studies, 104 as a primary outcome
- Stopped early32 studies, 14 as a primary outcome
- Status unknown131 studies, 54 as a primary outcome
What they test
- Behavioral67 studies, 20 as a primary outcome
- Drug194 studies, 68 as a primary outcome
- Device76 studies, 35 as a primary outcome
- Dietary supplement11 studies, 6 as a primary outcome
- Procedure61 studies, 20 as a primary outcome
- Diagnostic test33 studies, 13 as a primary outcome
- Biological4 studies, 2 as a primary outcome
- Radiation4 studies, 2 as a primary outcome
- Combination product2 studies, 0 as a primary outcome
- Genetic1 studies, 0 as a primary outcome
- Other151 studies, 53 as a primary outcome
- None given103 studies, 45 as a primary outcome
Intervention types as registered. A study can list several; observational studies often list none.
Where their sites are
- United States130 studies, 39 as a primary outcome
- China118 studies, 43 as a primary outcome
- Türkiye42 studies, 32 as a primary outcome
- Germany40 studies, 13 as a primary outcome
- France25 studies, 12 as a primary outcome
- Canada21 studies, 8 as a primary outcome
- Italy19 studies, 12 as a primary outcome
- United Kingdom18 studies, 2 as a primary outcome
- Denmark17 studies, 6 as a primary outcome
- Chile16 studies, 2 as a primary outcome
- Belgium15 studies, 5 as a primary outcome
- Egypt12 studies, 6 as a primary outcome
53 countries in all. A study with sites in several counts in each; 52 list no site.
Reported results
Completed studies with results posted on ClinicalTrials.gov, a results paper the registry links to the study, or both.
Completed delirium, surgery and intensive care studies: 99 of 264, 38%
Every completed study with a cognitive outcome: 3,626 of 7,953, 46%
| Results | Completed delirium, surgery and intensive care studies | Every completed study |
|---|---|---|
| Results on ClinicalTrials.gov and a paper | 15, 6% | 776, 10% |
| Results on ClinicalTrials.gov only | 25, 9% | 1,139, 14% |
| A results paper only | 59, 22% | 1,711, 22% |
| Neither | 165, 63% | 4,327, 54% |
How many participants they enroll
- Phase 293 median, 62 to 126
- Phase 3290 median, 89 to 788
- Phase 4136 median, 76 to 300
- Not applicable107 median, 53 to 276
- Observational150 median, 65 to 360
Show as a table
| Phase | Studies with a size | Median | Middle half |
|---|---|---|---|
| Phase 2 | 22 | 93 | 62 to 126 |
| Phase 3 | 24 | 290 | 89 to 788 |
| Phase 4 | 61 | 136 | 76 to 300 |
| Not applicable | 268 | 107 | 53 to 276 |
| Observational | 217 | 150 | 65 to 360 |
When the cognitive outcome is measured
Latest time point of each outcome
- Within a day59 outcomes, 29 as a primary outcome
- Up to 4 weeks117 outcomes, 75 as a primary outcome
- 1 to 3 months63 outcomes, 29 as a primary outcome
- 3 to 6 months47 outcomes, 13 as a primary outcome
- 6 to 12 months84 outcomes, 32 as a primary outcome
- 1 to 2 years11 outcomes, 1 as a primary outcome
- Over 2 years21 outcomes, 10 as a primary outcome
- No duration given22 outcomes, 13 as a primary outcome
A test as a primary outcomeOnly in secondary or other outcomes
402 of the 424 outcome measures give a duration. A single visit counts as within a day.
Median time to the primary outcome, by test
| Test | Primary outcomes | Median |
|---|---|---|
| Trail Making Test | 32 | 3 weeks |
| Verbal Learning | 28 | 3 weeks |
| Stroop Color-Word Test | 23 | 2 weeks |
| Digit Span Test | 20 | 1 week |
| Verbal Fluency | 18 | 13 weeks |
| Symbol Coding | 11 | 2 weeks |
Explore the delirium, surgery and intensive care studies
197 studies match. 94 name a library test in a primary outcome. Median size 121 participants. Median time to the primary outcome: 4 weeks.
Loading 197 studies; the filters turn on when they arrive.
2026 is partly planned starts. Not shown: 1 planned to start after 2026.
Show as a table
| Start year | Studies | As a primary outcome |
|---|---|---|
| 2000 | 0 | 0 |
| 2001 | 0 | 0 |
| 2002 | 0 | 0 |
| 2003 | 0 | 0 |
| 2004 | 1 | 1 |
| 2005 | 0 | 0 |
| 2006 | 1 | 1 |
| 2007 | 3 | 0 |
| 2008 | 3 | 2 |
| 2009 | 3 | 2 |
| 2010 | 2 | 0 |
| 2011 | 3 | 2 |
| 2012 | 3 | 2 |
| 2013 | 7 | 5 |
| 2014 | 11 | 8 |
| 2015 | 11 | 7 |
| 2016 | 8 | 5 |
| 2017 | 15 | 5 |
| 2018 | 12 | 3 |
| 2019 | 15 | 9 |
| 2020 | 16 | 9 |
| 2021 | 9 | 4 |
| 2022 | 15 | 8 |
| 2023 | 23 | 5 |
| 2024 | 13 | 6 |
| 2025 | 10 | 4 |
| 2026 | 12 | 6 |
Library tests named most
Largest condition groups
Phases
Participants
Lead sponsor: industry 4, other 193. Interventional 123, observational 74.
As a primary outcomeSecondary or other outcome
The studies, newest registration first
Each number opens the study's record on ClinicalTrials.gov.
| Study | Start | Phase | Conditions | Participants | Lead sponsor | Status | Library tests named, with the latest time point |
|---|---|---|---|---|---|---|---|
| NCT07895407 | Start2025 | PhasePhase 4 | ConditionsDelirium, surgery and intensive care | Participants148 | Lead sponsorOther | StatusRecruiting | Library tests named
|
| NCT07885085 | Start2027 | PhaseObservational | ConditionsMild cognitive impairment, Substance use and addiction, Delirium, surgery and intensive care, Pain and fatigue | Participants552 | Lead sponsorOther | StatusNot yet recruiting | Library tests named
|
| NCT07872982 | Start2026 | PhaseNot applicable | ConditionsDelirium, surgery and intensive care | Participants304 | Lead sponsorIndustry | StatusNot yet recruiting | Library tests named
|
| NCT07716800 | Start2026 | PhaseObservational | ConditionsCancer, Delirium, surgery and intensive care | Participants205 | Lead sponsorOther | StatusNot yet recruiting | Library tests named
|
| NCT07689500 | Start2025 | PhaseNot applicable | ConditionsDelirium, surgery and intensive care, Cardiovascular disease | Participants153 | Lead sponsorOther | StatusCompleted | Library tests named
|
| NCT07659431 | Start2026 | PhaseObservational | ConditionsDelirium, surgery and intensive care | Participants114 | Lead sponsorOther | StatusNot yet recruiting | Library tests named
|
| NCT07641153 | Start2026 | PhaseNot applicable | ConditionsDelirium, surgery and intensive care | Participants90 | Lead sponsorOther | StatusRecruiting | Library tests named
|
| NCT07626567 | Start2026 | PhaseObservational | ConditionsDelirium, surgery and intensive care, Cardiovascular disease | Participants500 | Lead sponsorOther | StatusNot yet recruiting | Library tests named
|
| NCT07610655 | Start2026 | PhaseNot applicable | ConditionsDepression and bipolar disorder, Delirium, surgery and intensive care | Participants40 | Lead sponsorOther | StatusRecruiting | Library tests named
|
| NCT07598552 | Start2026 | PhaseObservational | ConditionsDelirium, surgery and intensive care | Participants48 | Lead sponsorOther | StatusRecruiting | Library tests named
|
| NCT07580183 | Start2024 | PhaseNot applicable | ConditionsDelirium, surgery and intensive care, Epilepsy | Participants620 | Lead sponsorOther | StatusRecruiting | Library tests named
|
| NCT07533370 | Start2026 | PhaseNot applicable | ConditionsDelirium, surgery and intensive care | Participants300 | Lead sponsorOther | StatusNot yet recruiting | Library tests named
|
| NCT07452939 | Start2026 | PhaseNot applicable | ConditionsDementia and Alzheimer's, Delirium, surgery and intensive care | Participants40 | Lead sponsorOther | StatusRecruiting | Library tests named
|
| NCT07401641 | Start2025 | PhaseNot applicable | ConditionsCancer, Delirium, surgery and intensive care, Pain and fatigue | Participants60 | Lead sponsorOther | StatusRecruiting | Library tests named
|
| NCT07314762 | Start2023 | PhaseObservational | ConditionsAging, frailty and exercise, Delirium, surgery and intensive care | Participants1,200 | Lead sponsorOther | StatusRecruiting | Library tests named
|
| NCT07294092 | Start2026 | PhaseEarly phase 1 | ConditionsDelirium, surgery and intensive care, Pain and fatigue | Participants60 | Lead sponsorOther | StatusRecruiting | Library tests named
|
| NCT07290712 | Start2026 | PhaseObservational | ConditionsDelirium, surgery and intensive care | Participants5,000 | Lead sponsorOther | StatusRecruiting | Library tests named
|
| NCT07290205 | Start2026 | PhaseEarly phase 1 | ConditionsDelirium, surgery and intensive care, Pain and fatigue | Participants60 | Lead sponsorOther | StatusRecruiting | Library tests named
|
| NCT07180407 | Start2025 | PhaseObservational | ConditionsDepression and bipolar disorder, Sleep and sleep disorders, Anxiety, PTSD and OCD, Delirium, surgery and intensive care, Pain and fatigue | Participants800 | Lead sponsorOther | StatusRecruiting | Library tests named
|
| NCT07158177 | Start2025 | PhaseNot applicable | ConditionsDelirium, surgery and intensive care | Participants40 | Lead sponsorOther | StatusRecruiting | Library tests named
|
| NCT07074262 | Start2024 | PhaseNot applicable | ConditionsDelirium, surgery and intensive care | Participants114 | Lead sponsorOther | StatusCompleted | Library tests named
|
| NCT07051720 | Start2022 | PhaseNot applicable | ConditionsDelirium, surgery and intensive care | Participants180 | Lead sponsorOther | StatusRecruiting | Library tests named
|
| NCT06869876 | Start2025 | PhaseObservational | ConditionsDelirium, surgery and intensive care | Participants75 | Lead sponsorOther | StatusCompleted | Library tests named
|
| NCT06846333 | Start2025 | PhaseObservational | ConditionsSubstance use and addiction, Delirium, surgery and intensive care | Participants60 | Lead sponsorOther | StatusNot yet recruiting | Library tests named
|
| NCT06809218 | Start2022 | PhasePhase 3 | ConditionsAnxiety, PTSD and OCD, Delirium, surgery and intensive care | Participants312 | Lead sponsorIndustry | StatusActive, not recruiting | Library tests named
|
Questions, answered from the data
Which cognitive test do delirium, surgery and intensive care trials use most?
The Trail Making Test: 69 of the 619 registered studies name it in an outcome measure, 11%. Next come Verbal Learning (51) and Verbal Fluency (46).
Which cognitive test do delirium, surgery and intensive care trials use most as a primary outcome?
The Trail Making Test, named in a primary outcome by 34 studies. 234 of the 619 studies, 38%, name a cognitive test in a primary outcome.
How many participants does a phase 2 delirium, surgery and intensive care trial enroll?
Half of the phase 2 delirium, surgery and intensive care studies enroll 93 participants or fewer, and the middle half enroll 62 to 126. 22 of them give a size.
How long after the start do delirium, surgery and intensive care trials measure a cognitive outcome?
Half of the primary outcomes that name a library test are measured within 4 weeks of the start, and the middle half from 1 week to 6 months. 189 primary outcomes give a duration.
Which cognitive tests do delirium, surgery and intensive care trials use together?
The Trail Making Test with Verbal Learning most often: 23 studies name both. Next, the Stroop Color-Word Test with Verbal Learning (22).
How many completed delirium, surgery and intensive care trials have reported results?
99 of the 264 completed delirium, surgery and intensive care studies, 38%, have reported results: 40 posted them on ClinicalTrials.gov, 74 have a results paper linked to the registry record, and 15 did both. The other 165 show neither. Of all completed studies with a cognitive outcome, 46% have reported results.
How the studies are counted
For each test family, the census runs ClinicalTrials.gov's own outcome search for the family's names and reads every study first posted by the day the family was counted. These studies were read on 10 November 2026. A study counts once on a page, however many tests it names. Counts for a test cover every version of the task under any of its names, so a page can count studies that used a commercial version.
The census adds two things to each record and changes nothing in it: which outcome list names the test (primary, then secondary, then other), and the condition groups, matched on the study's condition names and MeSH terms. A study can fall in several groups; one whose only condition is cognitive impairment or decline falls in “Cognitive impairment and decline”. Studies that name only instruments outside the library count in every total and share but are not listed.
A second read on 10 November 2026 added each study's overall status, whether results are posted, its intervention types, the countries of its sites and the time frame of the outcome that names each test. A time frame counts by the latest time point it names: “Baseline, 12 and 24 weeks” is 24 weeks, a single visit is within a day, and one that names no duration, such as “end of treatment”, is left out of the timings.
A third read on 10 November 2026 added the papers the registry links to each study: those its sponsor lists as reporting results, and those PubMed links to it through the study's NCT number. A study has a results paper when one of them came out in or after the month of its primary completion and PubMed does not class it as a protocol, review or comment. A paper that never gives the NCT number is not linked, so some studies counted as reporting neither did publish.
Source: ClinicalTrials.gov, a database of the U.S. National Library of Medicine, which does not endorse these pages. Every study line is in the data release 2.1.0, and the explorer's own file is clinical-trials-studies.json.
Plan the cognitive outcomes of a delirium, surgery and intensive care trial
Choose tests with a record in registered trials, and run them in a browser at every site, on the same version each visit.