Clinical trials data

Digit Span Test in mild cognitive impairment trials: 169 registered studies

Every registered mild cognitive impairment study on ClinicalTrials.gov that names the Digit Span Test in an outcome measure: how often it is a primary outcome, the tests named with it, how large the studies are and when they measure it.

Registered mild cognitive impairment studies name it in an outcome measure: 169
Name it in a primary outcome, 46%: 77 of 169
Of the condition's 859 studies name it, against 10% of all registered studies: 20%; Other conditions
Median participants per study: 60; By phase

Try the Digit Span Test

Tests named in the same studies

The library tests that mild cognitive impairment studies naming the Digit Span Test name most often beside it.

1
Trail Making Test95 studies, 35 as a primary outcome
2
Verbal Fluency67 studies, 28 as a primary outcome
3
Verbal Learning59 studies, 32 as a primary outcome
4
Category Fluency39 studies, 18 as a primary outcome
5
Stroop Color-Word Test39 studies, 13 as a primary outcome
6
Symbol Coding32 studies, 19 as a primary outcome
7
Short Story Recall29 studies, 14 as a primary outcome
8
Picture Naming Test27 studies, 9 as a primary outcome
9
Clock Drawing Task16 studies, 9 as a primary outcome
10
Complex Figure Copy and Recall11 studies, 2 as a primary outcome

A test as a primary outcomeOnly in secondary or other outcomes

Studies by start year

Each study counted once. 2026 is partly planned starts.

A test as a primary outcomeOnly in secondary or other outcomes

Show as a table

Registered studies by start year
Start year	Studies	A test as a primary outcome
2000	0	0
2001	0	0
2002	0	0
2003	1	1
2004	0	0
2005	0	0
2006	0	0
2007	0	0
2008	2	1
2009	1	1
2010	6	2
2011	2	0
2012	4	2
2013	2	0
2014	3	2
2015	8	4
2016	7	5
2017	6	3
2018	4	1
2019	10	3
2020	14	5
2021	15	10
2022	12	5
2023	15	8
2024	22	12
2025	19	7
2026	16	5

Phases and study sizes

By phase

Phase 13 studies, 1 as a primary outcome
Phase 1/22 studies, 1 as a primary outcome
Phase 214 studies, 6 as a primary outcome
Phase 33 studies, 2 as a primary outcome
Phase 43 studies, 0 as a primary outcome
Not applicable135 studies, 62 as a primary outcome
Observational9 studies, 5 as a primary outcome

Participants per study

Phase 286 median, 52 to 176
Not applicable60 median, 40 to 113

Participants per study. The bar spans the middle half of the studies in each phase, the mark is the median, and the axis is logarithmic. Phases with fewer than 10 studies that give a size are left out.

Show as a table

Participants per mild cognitive impairment study that names the Digit Span Test, by phase
Phase	Studies with a size	Median	Middle half
Phase 2	13	86	52 to 176
Not applicable	135	60	40 to 113

When mild cognitive impairment trials measure it

Half of the primary outcomes that name the Digit Span Test are measured within 13 weeks of the start, and the middle half from 8 weeks to 6 months. 69 primary outcomes give a duration.

Latest time point of each outcome

Within a day11 outcomes, 7 as a primary outcome
Up to 4 weeks12 outcomes, 3 as a primary outcome
1 to 3 months52 outcomes, 27 as a primary outcome
3 to 6 months35 outcomes, 18 as a primary outcome
6 to 12 months28 outcomes, 6 as a primary outcome
1 to 2 years12 outcomes, 6 as a primary outcome
Over 2 years5 outcomes, 2 as a primary outcome
No duration given14 outcomes, 8 as a primary outcome

A test as a primary outcomeOnly in secondary or other outcomes

155 of the 169 outcome measures give a duration. A single visit counts as within a day.

Status, results, interventions and countries

Status

Recruiting32 studies, 17 as a primary outcome
Not yet recruiting16 studies, 6 as a primary outcome
Active, not recruiting5 studies, 2 as a primary outcome
Completed78 studies, 32 as a primary outcome
Stopped early9 studies, 5 as a primary outcome
Status unknown29 studies, 15 as a primary outcome

What they test

Behavioral62 studies, 30 as a primary outcome
Drug18 studies, 6 as a primary outcome
Device37 studies, 15 as a primary outcome
Dietary supplement14 studies, 6 as a primary outcome
Procedure8 studies, 4 as a primary outcome
Diagnostic test3 studies, 2 as a primary outcome
Biological1 studies, 1 as a primary outcome
Combination product3 studies, 2 as a primary outcome
Other49 studies, 25 as a primary outcome
None given4 studies, 2 as a primary outcome

Intervention types as registered. A study can list several; observational studies often list none.

31 countries in all. A study with sites in several counts in each; 17 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 mild cognitive impairment studies that name the Digit Span Test: 34 of 78, 44%

Every completed study with a cognitive outcome: 3,626 of 7,953, 46%

Completed mild cognitive impairment studies that name the Digit Span Test and every completed study, by how they reported results
Results	Completed mild cognitive impairment studies that name the Digit Span Test	Every completed study
Results on ClinicalTrials.gov and a paper	6, 8%	776, 10%
Results on ClinicalTrials.gov only	11, 14%	1,139, 14%
A results paper only	17, 22%	1,711, 22%
Neither	44, 56%	4,327, 54%

The 169 studies

Filter by phase, sponsor, status, country, intervention, outcome list, size and start year. Each study links to its record on ClinicalTrials.gov.

169 studies match. 77 name the Digit Span Test in a primary outcome. Median size 60 participants. Median time to the primary outcome: 13 weeks.

Loading 169 studies; the filters turn on when they arrive.

By start year

2026 is partly planned starts.

Show as a table

Matching studies by start year
Start year	Studies	As a primary outcome
2000	0	0
2001	0	0
2002	0	0
2003	1	1
2004	0	0
2005	0	0
2006	0	0
2007	0	0
2008	2	1
2009	1	1
2010	6	2
2011	2	0
2012	4	2
2013	2	0
2014	3	2
2015	8	4
2016	7	5
2017	6	3
2018	4	1
2019	10	3
2020	14	5
2021	15	10
2022	12	5
2023	15	8
2024	22	12
2025	19	7
2026	16	5

Library tests named most

Largest condition groups

Mild cognitive impairment169 studies, 77 as a primary outcome
Dementia and Alzheimer's49 studies, 20 as a primary outcome
Aging, frailty and exercise22 studies, 11 as a primary outcome
Healthy volunteers10 studies, 5 as a primary outcome
Depression and bipolar disorder5 studies, 4 as a primary outcome
Obesity and diabetes4 studies, 1 as a primary outcome
Sleep and sleep disorders4 studies, 3 as a primary outcome
Parkinson's disease3 studies, 0 as a primary outcome
Anxiety, PTSD and OCD3 studies, 3 as a primary outcome
Cardiovascular disease3 studies, 1 as a primary outcome
Brain injury and concussion2 studies, 0 as a primary outcome
Cancer2 studies, 2 as a primary outcome

Phases

Participants

Lead sponsor: industry 13, other 156. Interventional 160, observational 9.

As a primary outcomeSecondary or other outcomeThe Digit Span Test

The studies, newest registration first

Each number opens the study's record on ClinicalTrials.gov.

Registered studies that match the filters, newest registration first, with the library tests each one names and the outcome list that names them.
Study	Start	Phase	Conditions	Participants	Lead sponsor	Status	Library tests named, with the latest time point
NCT07883148	Start2024	PhaseNot applicable	ConditionsDementia and Alzheimer's, Mild cognitive impairment	Participants52	Lead sponsorOther	StatusCompleted	Library tests named Trail Making TestSecondary8 months Verbal LearningSecondary8 months Verbal FluencySecondary8 months Digit Span TestSecondary8 months Complex Figure Copy and RecallSecondary8 months
NCT07863518	Start2024	PhaseNot applicable	ConditionsMild cognitive impairment	Participants61	Lead sponsorOther	StatusCompleted	Library tests named Digit Span TestSecondary7 months Arithmetic Fluency TaskPrimary7 months
NCT07799584	Start2026	PhaseNot applicable	ConditionsMild cognitive impairment	Participants120	Lead sponsorOther	StatusRecruiting	Library tests named Verbal LearningPrimary6 months Digit Span TestPrimary8 weeks N-Back TaskPrimary8 weeks Go/No-Go TaskPrimary8 weeks Mnemonic Similarity TaskPrimary6 months
NCT07766993	Start2026	PhaseNot applicable	ConditionsDementia and Alzheimer's, Mild cognitive impairment	Participants100	Lead sponsorOther	StatusNot yet recruiting	Library tests named Digit Span TestPrimary12 months
NCT07735910	Start2026	PhaseNot applicable	ConditionsMild cognitive impairment, Depression and bipolar disorder, Sleep and sleep disorders, Anxiety, PTSD and OCD	Participants60	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestPrimary2 weeks Stroop Color-Word TestPrimary2 weeks Digit Span TestPrimary2 weeks
NCT07731334	Start2026	PhaseNot applicable	ConditionsDementia and Alzheimer's, Mild cognitive impairment	Participants384	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestSecondary12 months Stroop Color-Word TestSecondary12 months Verbal LearningSecondary12 months Verbal FluencySecondary12 months Digit Span TestSecondary12 months Complex Figure Copy and RecallSecondary12 months Corsi Block-Tapping TestSecondary12 months Oddball Target DetectionSecondary
NCT07672977	Start2025	PhaseNot applicable	ConditionsDementia and Alzheimer's, Mild cognitive impairment	Participants30	Lead sponsorIndustry	StatusRecruiting	Library tests named Verbal LearningOther outcome7 months Digit Span TestOther outcome7 months Short Story RecallOther outcome7 months Symbol Scan TaskOther outcome7 months Word Pair LearningOther outcome7 months
NCT07667478	Start2026	PhaseNot applicable	ConditionsDementia and Alzheimer's, Mild cognitive impairment	Participants40	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestPrimary6 months Verbal LearningPrimary6 months Digit Span TestPrimary6 months Picture Naming TestPrimary6 months
NCT07656389	Start2026	PhaseObservational	ConditionsMild cognitive impairment, Aging, frailty and exercise	Participants192	Lead sponsorOther	StatusNot yet recruiting	Library tests named Digit Span TestSecondarysame day Continuous Performance TestSecondarysame day
NCT07652775	Start2026	PhaseNot applicable	ConditionsMild cognitive impairment, Depression and bipolar disorder	Participants45	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestSecondary5 weeks Stroop Color-Word TestSecondary5 weeks Verbal LearningSecondary5 weeks Digit Span TestSecondary5 weeks
NCT07650318	Start2026	PhaseNot applicable	ConditionsMild cognitive impairment, Obesity and diabetes	Participants40	Lead sponsorOther	StatusRecruiting	Library tests named Digit Span TestSecondary6 months Category FluencySecondary6 months Picture Naming TestSecondary6 months Short Story RecallSecondary6 months Delayed Recall ModuleSecondary6 months
NCT07642518	Start2026	PhaseNot applicable	ConditionsMild cognitive impairment, Obesity and diabetes	Participants38	Lead sponsorOther	StatusNot yet recruiting	Library tests named Trail Making TestSecondary6 months Stroop Color-Word TestSecondary6 months Digit Span TestSecondary6 months Category FluencySecondary6 months Picture Naming TestSecondary6 months Short Story RecallSecondary6 months
NCT07636538	Start2026	PhaseNot applicable	ConditionsMild cognitive impairment, Stroke, Parkinson's disease	Participants30	Lead sponsorOther	StatusNot yet recruiting	Library tests named Trail Making TestSecondary Stroop Color-Word TestSecondary Digit Span TestSecondary
NCT07629349	Start2020	PhaseObservational	ConditionsDementia and Alzheimer's, Mild cognitive impairment	Participants600	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestPrimary6 months Verbal LearningPrimary6 months Digit Span TestPrimary6 months Complex Figure Copy and RecallPrimary6 months Matrix ReasoningPrimary6 months Block Copy TestPrimary6 months
NCT07598409	Start2025	PhaseNot applicable	ConditionsMild cognitive impairment, Healthy volunteers, Aging, frailty and exercise	Participants156	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestSecondary13 weeks Digit Span TestSecondary13 weeks
NCT07517380	Start2026	PhaseNot applicable	ConditionsMild cognitive impairment	Participants40	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestPrimary6 months Stroop Color-Word TestPrimary6 months Verbal LearningPrimary6 months Verbal FluencyPrimary6 months Digit Span TestPrimary6 months Picture Naming TestPrimary6 months Complex Figure Copy and RecallPrimary6 months Matrix ReasoningPrimary6 months Corsi Block-Tapping TestPrimary6 months
NCT07512193	Start2026	PhaseNot applicable	ConditionsMild cognitive impairment	Participants10	Lead sponsorOther	StatusNot yet recruiting	Library tests named Trail Making TestSecondary4 weeks Verbal LearningPrimary4 weeks Verbal FluencySecondary4 weeks Digit Span TestSecondary4 weeks Picture Naming TestSecondary4 weeks Mnemonic Similarity TaskSecondary4 weeks
NCT07497334	Start2025	PhaseNot applicable	ConditionsMild cognitive impairment, Aging, frailty and exercise	Participants45	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestSecondary6 months Stroop Color-Word TestSecondary6 months Digit Span TestSecondary6 months Symbol CodingSecondary6 months Task Switching TestSecondary6 months
NCT07389655	Start2026	PhaseNot applicable	ConditionsMild cognitive impairment	Participants30	Lead sponsorOther	StatusNot yet recruiting	Library tests named Digit Span TestSecondary12 weeks Category FluencySecondary12 weeks Short Story RecallSecondary12 weeks
NCT07385937	Start2026	PhaseNot applicable	ConditionsDementia and Alzheimer's, Mild cognitive impairment	Participants150	Lead sponsorOther	StatusNot yet recruiting	Library tests named Trail Making TestSecondary18 months Verbal FluencySecondary18 months Digit Span TestSecondary18 months Category FluencySecondary18 months Clock Drawing TaskSecondary18 months Cancellation TestSecondary18 months Delayed Recall ModuleSecondary18 months
NCT07376135	Start2026	PhaseNot applicable	ConditionsDementia and Alzheimer's, Mild cognitive impairment	Participants300	Lead sponsorOther	StatusNot yet recruiting	Library tests named Trail Making TestOther outcome18 months Stroop Color-Word TestOther outcome18 months Verbal LearningOther outcome18 months Digit Span TestOther outcome18 months Symbol CodingOther outcome18 months Short Story RecallOther outcome18 months Complex Figure Copy and RecallOther outcome18 months
NCT07334392	Start2025	PhaseNot applicable	ConditionsMild cognitive impairment	Participants45	Lead sponsorOther	StatusRecruiting	Library tests named Stroop Color-Word TestPrimary12 weeks Verbal FluencyPrimary12 weeks Digit Span TestPrimary12 weeks
NCT07321821	Start2025	PhaseNot applicable	ConditionsMild cognitive impairment	Participants60	Lead sponsorOther	StatusActive, not recruiting	Library tests named Stroop Color-Word TestSecondary9 weeks Verbal LearningSecondary9 weeks Verbal FluencySecondary9 weeks Digit Span TestSecondary9 weeks Complex Figure Copy and RecallSecondary9 weeks
NCT07318038	Start2025	PhaseNot applicable	ConditionsMild cognitive impairment	Participants20	Lead sponsorOther	StatusCompleted	Library tests named Digit Span TestSecondary1 week
NCT07241598	Start2025	PhaseNot applicable	ConditionsDementia and Alzheimer's, Mild cognitive impairment	Participants70	Lead sponsorOther	StatusNot yet recruiting	Library tests named Trail Making TestSecondary12 months Verbal FluencySecondary12 months Digit Span TestSecondary12 months Symbol CodingSecondary12 months Go/No-Go TaskSecondary12 months Category FluencySecondary12 months

Questions, answered from the data

How many mild cognitive impairment trials use the Digit Span Test?

169 registered mild cognitive impairment studies on ClinicalTrials.gov name it in an outcome measure, 77 of them in a primary outcome: 20% of the condition's 859 studies with a cognitive outcome, against 10% of all of them. It is the 4th most named test in mild cognitive impairment trials.

Which tests do mild cognitive impairment trials use with the Digit Span Test?

The Trail Making Test (95 studies), Verbal Fluency (67 studies) and Verbal Learning (59 studies).

How many participants do phase 2 mild cognitive impairment trials that use the Digit Span Test enroll?

Half of the phase 2 studies that name it enroll 86 participants or fewer, and the middle half enroll 52 to 176. 13 of them give a size.

When do mild cognitive impairment trials measure the Digit Span Test?

Half of the primary outcomes that name the Digit Span Test are measured within 13 weeks of the start, and the middle half from 8 weeks to 6 months. 69 primary outcomes give a duration.

How many completed mild cognitive impairment trials that use the Digit Span Test have reported results?

34 of the 78 completed studies that name it, 44%, have reported results: 17 posted them on ClinicalTrials.gov, 23 have a results paper linked to the registry record, and 6 did both. The other 44 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.

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Clinical trials data

Digit Span Test in mild cognitive impairment trials: 169 registered studies

Registered mild cognitive impairment studies name it in an outcome measure: 169
Name it in a primary outcome, 46%: 77 of 169
Of the condition's 859 studies name it, against 10% of all registered studies: 20%; Other conditions
Median participants per study: 60; By phase

Try the Digit Span Test

Tests named in the same studies

The library tests that mild cognitive impairment studies naming the Digit Span Test name most often beside it.

1
Trail Making Test95 studies, 35 as a primary outcome
2
Verbal Fluency67 studies, 28 as a primary outcome
3
Verbal Learning59 studies, 32 as a primary outcome
4
Category Fluency39 studies, 18 as a primary outcome
5
Stroop Color-Word Test39 studies, 13 as a primary outcome
6
Symbol Coding32 studies, 19 as a primary outcome
7
Short Story Recall29 studies, 14 as a primary outcome
8
Picture Naming Test27 studies, 9 as a primary outcome
9
Clock Drawing Task16 studies, 9 as a primary outcome
10
Complex Figure Copy and Recall11 studies, 2 as a primary outcome

A test as a primary outcomeOnly in secondary or other outcomes

Studies by start year

Each study counted once. 2026 is partly planned starts.

A test as a primary outcomeOnly in secondary or other outcomes

Show as a table

Registered studies by start year
Start year	Studies	A test as a primary outcome
2000	0	0
2001	0	0
2002	0	0
2003	1	1
2004	0	0
2005	0	0
2006	0	0
2007	0	0
2008	2	1
2009	1	1
2010	6	2
2011	2	0
2012	4	2
2013	2	0
2014	3	2
2015	8	4
2016	7	5
2017	6	3
2018	4	1
2019	10	3
2020	14	5
2021	15	10
2022	12	5
2023	15	8
2024	22	12
2025	19	7
2026	16	5

Phases and study sizes

By phase

Phase 13 studies, 1 as a primary outcome
Phase 1/22 studies, 1 as a primary outcome
Phase 214 studies, 6 as a primary outcome
Phase 33 studies, 2 as a primary outcome
Phase 43 studies, 0 as a primary outcome
Not applicable135 studies, 62 as a primary outcome
Observational9 studies, 5 as a primary outcome

Participants per study

Phase 286 median, 52 to 176
Not applicable60 median, 40 to 113

Show as a table

Participants per mild cognitive impairment study that names the Digit Span Test, by phase
Phase	Studies with a size	Median	Middle half
Phase 2	13	86	52 to 176
Not applicable	135	60	40 to 113

When mild cognitive impairment trials measure it

Half of the primary outcomes that name the Digit Span Test are measured within 13 weeks of the start, and the middle half from 8 weeks to 6 months. 69 primary outcomes give a duration.

Latest time point of each outcome

Within a day11 outcomes, 7 as a primary outcome
Up to 4 weeks12 outcomes, 3 as a primary outcome
1 to 3 months52 outcomes, 27 as a primary outcome
3 to 6 months35 outcomes, 18 as a primary outcome
6 to 12 months28 outcomes, 6 as a primary outcome
1 to 2 years12 outcomes, 6 as a primary outcome
Over 2 years5 outcomes, 2 as a primary outcome
No duration given14 outcomes, 8 as a primary outcome

A test as a primary outcomeOnly in secondary or other outcomes

155 of the 169 outcome measures give a duration. A single visit counts as within a day.

Status, results, interventions and countries

Status

Recruiting32 studies, 17 as a primary outcome
Not yet recruiting16 studies, 6 as a primary outcome
Active, not recruiting5 studies, 2 as a primary outcome
Completed78 studies, 32 as a primary outcome
Stopped early9 studies, 5 as a primary outcome
Status unknown29 studies, 15 as a primary outcome

What they test

Behavioral62 studies, 30 as a primary outcome
Drug18 studies, 6 as a primary outcome
Device37 studies, 15 as a primary outcome
Dietary supplement14 studies, 6 as a primary outcome
Procedure8 studies, 4 as a primary outcome
Diagnostic test3 studies, 2 as a primary outcome
Biological1 studies, 1 as a primary outcome
Combination product3 studies, 2 as a primary outcome
Other49 studies, 25 as a primary outcome
None given4 studies, 2 as a primary outcome

Intervention types as registered. A study can list several; observational studies often list none.

31 countries in all. A study with sites in several counts in each; 17 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 mild cognitive impairment studies that name the Digit Span Test: 34 of 78, 44%

Every completed study with a cognitive outcome: 3,626 of 7,953, 46%

Completed mild cognitive impairment studies that name the Digit Span Test and every completed study, by how they reported results
Results	Completed mild cognitive impairment studies that name the Digit Span Test	Every completed study
Results on ClinicalTrials.gov and a paper	6, 8%	776, 10%
Results on ClinicalTrials.gov only	11, 14%	1,139, 14%
A results paper only	17, 22%	1,711, 22%
Neither	44, 56%	4,327, 54%

The 169 studies

Filter by phase, sponsor, status, country, intervention, outcome list, size and start year. Each study links to its record on ClinicalTrials.gov.

169 studies match. 77 name the Digit Span Test in a primary outcome. Median size 60 participants. Median time to the primary outcome: 13 weeks.

Loading 169 studies; the filters turn on when they arrive.

By start year

2026 is partly planned starts.

Show as a table

Matching studies by start year
Start year	Studies	As a primary outcome
2000	0	0
2001	0	0
2002	0	0
2003	1	1
2004	0	0
2005	0	0
2006	0	0
2007	0	0
2008	2	1
2009	1	1
2010	6	2
2011	2	0
2012	4	2
2013	2	0
2014	3	2
2015	8	4
2016	7	5
2017	6	3
2018	4	1
2019	10	3
2020	14	5
2021	15	10
2022	12	5
2023	15	8
2024	22	12
2025	19	7
2026	16	5

Library tests named most

Largest condition groups

Mild cognitive impairment169 studies, 77 as a primary outcome
Dementia and Alzheimer's49 studies, 20 as a primary outcome
Aging, frailty and exercise22 studies, 11 as a primary outcome
Healthy volunteers10 studies, 5 as a primary outcome
Depression and bipolar disorder5 studies, 4 as a primary outcome
Obesity and diabetes4 studies, 1 as a primary outcome
Sleep and sleep disorders4 studies, 3 as a primary outcome
Parkinson's disease3 studies, 0 as a primary outcome
Anxiety, PTSD and OCD3 studies, 3 as a primary outcome
Cardiovascular disease3 studies, 1 as a primary outcome
Brain injury and concussion2 studies, 0 as a primary outcome
Cancer2 studies, 2 as a primary outcome

Phases

Participants

Lead sponsor: industry 13, other 156. Interventional 160, observational 9.

As a primary outcomeSecondary or other outcomeThe Digit Span Test

The studies, newest registration first

Each number opens the study's record on ClinicalTrials.gov.

Registered studies that match the filters, newest registration first, with the library tests each one names and the outcome list that names them.
Study	Start	Phase	Conditions	Participants	Lead sponsor	Status	Library tests named, with the latest time point
NCT07883148	Start2024	PhaseNot applicable	ConditionsDementia and Alzheimer's, Mild cognitive impairment	Participants52	Lead sponsorOther	StatusCompleted	Library tests named Trail Making TestSecondary8 months Verbal LearningSecondary8 months Verbal FluencySecondary8 months Digit Span TestSecondary8 months Complex Figure Copy and RecallSecondary8 months
NCT07863518	Start2024	PhaseNot applicable	ConditionsMild cognitive impairment	Participants61	Lead sponsorOther	StatusCompleted	Library tests named Digit Span TestSecondary7 months Arithmetic Fluency TaskPrimary7 months
NCT07799584	Start2026	PhaseNot applicable	ConditionsMild cognitive impairment	Participants120	Lead sponsorOther	StatusRecruiting	Library tests named Verbal LearningPrimary6 months Digit Span TestPrimary8 weeks N-Back TaskPrimary8 weeks Go/No-Go TaskPrimary8 weeks Mnemonic Similarity TaskPrimary6 months
NCT07766993	Start2026	PhaseNot applicable	ConditionsDementia and Alzheimer's, Mild cognitive impairment	Participants100	Lead sponsorOther	StatusNot yet recruiting	Library tests named Digit Span TestPrimary12 months
NCT07735910	Start2026	PhaseNot applicable	ConditionsMild cognitive impairment, Depression and bipolar disorder, Sleep and sleep disorders, Anxiety, PTSD and OCD	Participants60	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestPrimary2 weeks Stroop Color-Word TestPrimary2 weeks Digit Span TestPrimary2 weeks
NCT07731334	Start2026	PhaseNot applicable	ConditionsDementia and Alzheimer's, Mild cognitive impairment	Participants384	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestSecondary12 months Stroop Color-Word TestSecondary12 months Verbal LearningSecondary12 months Verbal FluencySecondary12 months Digit Span TestSecondary12 months Complex Figure Copy and RecallSecondary12 months Corsi Block-Tapping TestSecondary12 months Oddball Target DetectionSecondary
NCT07672977	Start2025	PhaseNot applicable	ConditionsDementia and Alzheimer's, Mild cognitive impairment	Participants30	Lead sponsorIndustry	StatusRecruiting	Library tests named Verbal LearningOther outcome7 months Digit Span TestOther outcome7 months Short Story RecallOther outcome7 months Symbol Scan TaskOther outcome7 months Word Pair LearningOther outcome7 months
NCT07667478	Start2026	PhaseNot applicable	ConditionsDementia and Alzheimer's, Mild cognitive impairment	Participants40	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestPrimary6 months Verbal LearningPrimary6 months Digit Span TestPrimary6 months Picture Naming TestPrimary6 months
NCT07656389	Start2026	PhaseObservational	ConditionsMild cognitive impairment, Aging, frailty and exercise	Participants192	Lead sponsorOther	StatusNot yet recruiting	Library tests named Digit Span TestSecondarysame day Continuous Performance TestSecondarysame day
NCT07652775	Start2026	PhaseNot applicable	ConditionsMild cognitive impairment, Depression and bipolar disorder	Participants45	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestSecondary5 weeks Stroop Color-Word TestSecondary5 weeks Verbal LearningSecondary5 weeks Digit Span TestSecondary5 weeks
NCT07650318	Start2026	PhaseNot applicable	ConditionsMild cognitive impairment, Obesity and diabetes	Participants40	Lead sponsorOther	StatusRecruiting	Library tests named Digit Span TestSecondary6 months Category FluencySecondary6 months Picture Naming TestSecondary6 months Short Story RecallSecondary6 months Delayed Recall ModuleSecondary6 months
NCT07642518	Start2026	PhaseNot applicable	ConditionsMild cognitive impairment, Obesity and diabetes	Participants38	Lead sponsorOther	StatusNot yet recruiting	Library tests named Trail Making TestSecondary6 months Stroop Color-Word TestSecondary6 months Digit Span TestSecondary6 months Category FluencySecondary6 months Picture Naming TestSecondary6 months Short Story RecallSecondary6 months
NCT07636538	Start2026	PhaseNot applicable	ConditionsMild cognitive impairment, Stroke, Parkinson's disease	Participants30	Lead sponsorOther	StatusNot yet recruiting	Library tests named Trail Making TestSecondary Stroop Color-Word TestSecondary Digit Span TestSecondary
NCT07629349	Start2020	PhaseObservational	ConditionsDementia and Alzheimer's, Mild cognitive impairment	Participants600	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestPrimary6 months Verbal LearningPrimary6 months Digit Span TestPrimary6 months Complex Figure Copy and RecallPrimary6 months Matrix ReasoningPrimary6 months Block Copy TestPrimary6 months
NCT07598409	Start2025	PhaseNot applicable	ConditionsMild cognitive impairment, Healthy volunteers, Aging, frailty and exercise	Participants156	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestSecondary13 weeks Digit Span TestSecondary13 weeks
NCT07517380	Start2026	PhaseNot applicable	ConditionsMild cognitive impairment	Participants40	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestPrimary6 months Stroop Color-Word TestPrimary6 months Verbal LearningPrimary6 months Verbal FluencyPrimary6 months Digit Span TestPrimary6 months Picture Naming TestPrimary6 months Complex Figure Copy and RecallPrimary6 months Matrix ReasoningPrimary6 months Corsi Block-Tapping TestPrimary6 months
NCT07512193	Start2026	PhaseNot applicable	ConditionsMild cognitive impairment	Participants10	Lead sponsorOther	StatusNot yet recruiting	Library tests named Trail Making TestSecondary4 weeks Verbal LearningPrimary4 weeks Verbal FluencySecondary4 weeks Digit Span TestSecondary4 weeks Picture Naming TestSecondary4 weeks Mnemonic Similarity TaskSecondary4 weeks
NCT07497334	Start2025	PhaseNot applicable	ConditionsMild cognitive impairment, Aging, frailty and exercise	Participants45	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestSecondary6 months Stroop Color-Word TestSecondary6 months Digit Span TestSecondary6 months Symbol CodingSecondary6 months Task Switching TestSecondary6 months
NCT07389655	Start2026	PhaseNot applicable	ConditionsMild cognitive impairment	Participants30	Lead sponsorOther	StatusNot yet recruiting	Library tests named Digit Span TestSecondary12 weeks Category FluencySecondary12 weeks Short Story RecallSecondary12 weeks
NCT07385937	Start2026	PhaseNot applicable	ConditionsDementia and Alzheimer's, Mild cognitive impairment	Participants150	Lead sponsorOther	StatusNot yet recruiting	Library tests named Trail Making TestSecondary18 months Verbal FluencySecondary18 months Digit Span TestSecondary18 months Category FluencySecondary18 months Clock Drawing TaskSecondary18 months Cancellation TestSecondary18 months Delayed Recall ModuleSecondary18 months
NCT07376135	Start2026	PhaseNot applicable	ConditionsDementia and Alzheimer's, Mild cognitive impairment	Participants300	Lead sponsorOther	StatusNot yet recruiting	Library tests named Trail Making TestOther outcome18 months Stroop Color-Word TestOther outcome18 months Verbal LearningOther outcome18 months Digit Span TestOther outcome18 months Symbol CodingOther outcome18 months Short Story RecallOther outcome18 months Complex Figure Copy and RecallOther outcome18 months
NCT07334392	Start2025	PhaseNot applicable	ConditionsMild cognitive impairment	Participants45	Lead sponsorOther	StatusRecruiting	Library tests named Stroop Color-Word TestPrimary12 weeks Verbal FluencyPrimary12 weeks Digit Span TestPrimary12 weeks
NCT07321821	Start2025	PhaseNot applicable	ConditionsMild cognitive impairment	Participants60	Lead sponsorOther	StatusActive, not recruiting	Library tests named Stroop Color-Word TestSecondary9 weeks Verbal LearningSecondary9 weeks Verbal FluencySecondary9 weeks Digit Span TestSecondary9 weeks Complex Figure Copy and RecallSecondary9 weeks
NCT07318038	Start2025	PhaseNot applicable	ConditionsMild cognitive impairment	Participants20	Lead sponsorOther	StatusCompleted	Library tests named Digit Span TestSecondary1 week
NCT07241598	Start2025	PhaseNot applicable	ConditionsDementia and Alzheimer's, Mild cognitive impairment	Participants70	Lead sponsorOther	StatusNot yet recruiting	Library tests named Trail Making TestSecondary12 months Verbal FluencySecondary12 months Digit Span TestSecondary12 months Symbol CodingSecondary12 months Go/No-Go TaskSecondary12 months Category FluencySecondary12 months

Questions, answered from the data

How many mild cognitive impairment trials use the Digit Span Test?

Which tests do mild cognitive impairment trials use with the Digit Span Test?

The Trail Making Test (95 studies), Verbal Fluency (67 studies) and Verbal Learning (59 studies).

How many participants do phase 2 mild cognitive impairment trials that use the Digit Span Test enroll?

Half of the phase 2 studies that name it enroll 86 participants or fewer, and the middle half enroll 52 to 176. 13 of them give a size.

When do mild cognitive impairment trials measure the Digit Span Test?

Half of the primary outcomes that name the Digit Span Test are measured within 13 weeks of the start, and the middle half from 8 weeks to 6 months. 69 primary outcomes give a duration.

How many completed mild cognitive impairment trials that use the Digit Span Test have reported results?

How the studies are counted

Run the Digit Span Test in your trial

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Digit Span Test in mild cognitive impairment trials: 169 registered studies

Tests named in the same studies

Studies by start year

Phases and study sizes

By phase

Participants per study

When mild cognitive impairment trials measure it

Latest time point of each outcome

Status, results, interventions and countries

Status

What they test

Where their sites are

Reported results

The 169 studies

Library tests named most

Largest condition groups

Phases

Participants

The studies, newest registration first

Questions, answered from the data

How many mild cognitive impairment trials use the Digit Span Test?

Which tests do mild cognitive impairment trials use with the Digit Span Test?

How many participants do phase 2 mild cognitive impairment trials that use the Digit Span Test enroll?

When do mild cognitive impairment trials measure the Digit Span Test?

How many completed mild cognitive impairment trials that use the Digit Span Test have reported results?

More on the Digit Span Test and mild cognitive impairment

The Digit Span Test in other conditions

Other tests in mild cognitive impairment trials

How the studies are counted

Run the Digit Span Test in your trial

Digit Span Test in mild cognitive impairment trials: 169 registered studies

Tests named in the same studies

Studies by start year

Phases and study sizes

By phase

Participants per study

When mild cognitive impairment trials measure it

Latest time point of each outcome

Status, results, interventions and countries

Status

What they test

Where their sites are

Reported results

The 169 studies

Library tests named most

Largest condition groups

Phases

Participants

The studies, newest registration first

Questions, answered from the data

How many mild cognitive impairment trials use the Digit Span Test?

Which tests do mild cognitive impairment trials use with the Digit Span Test?

How many participants do phase 2 mild cognitive impairment trials that use the Digit Span Test enroll?

When do mild cognitive impairment trials measure the Digit Span Test?

How many completed mild cognitive impairment trials that use the Digit Span Test have reported results?

More on the Digit Span Test and mild cognitive impairment

The Digit Span Test in other conditions

Other tests in mild cognitive impairment trials

How the studies are counted

Run the Digit Span Test in your trial