Clinical trials data

Digit Span Test in sleep trials: 63 registered studies

Every registered sleep and sleep disorders 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 sleep and sleep disorders studies name it in an outcome measure: 63
Name it in a primary outcome, 37%: 23 of 63
Of the condition's 749 studies name it, against 10% of all registered studies: 8%; Other conditions
Median participants per study: 80; By phase

Try the Digit Span Test

Tests named in the same studies

The library tests that sleep and sleep disorders studies naming the Digit Span Test name most often beside it.

1
Trail Making Test24 studies, 7 as a primary outcome
2
Stroop Color-Word Test23 studies, 9 as a primary outcome
3
Verbal Fluency18 studies, 7 as a primary outcome
4
Verbal Learning17 studies, 5 as a primary outcome
5
Psychomotor Vigilance Task13 studies, 3 as a primary outcome
6
Symbol Coding11 studies, 4 as a primary outcome
7
N-Back Task10 studies, 2 as a primary outcome
8
Card Sorting Test (Berg)9 studies, 1 as a primary outcome
9
Go/No-Go Task9 studies, 1 as a primary outcome
10
Balloon Risk7 studies, 0 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	0	0
2004	1	0
2005	0	0
2006	0	0
2007	0	0
2008	0	0
2009	0	0
2010	2	1
2011	2	0
2012	2	0
2013	1	0
2014	1	0
2015	0	0
2016	1	1
2017	3	0
2018	3	1
2019	6	1
2020	5	3
2021	2	1
2022	2	0
2023	5	1
2024	9	5
2025	9	5
2026	9	4

Phases and study sizes

By phase

Phase 11 studies, 0 as a primary outcome
Phase 22 studies, 1 as a primary outcome
Phase 32 studies, 0 as a primary outcome
Phase 42 studies, 0 as a primary outcome
Not applicable48 studies, 18 as a primary outcome
Observational8 studies, 4 as a primary outcome

Participants per study

Not applicable70 median, 40 to 132

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 sleep and sleep disorders study that names the Digit Span Test, by phase
Phase	Studies with a size	Median	Middle half
Not applicable	48	70	40 to 132

When sleep trials measure it

Half of the primary outcomes that name the Digit Span Test are measured within 8 weeks of the start, and the middle half from 2 weeks to 6 months. 21 primary outcomes give a duration.

Latest time point of each outcome

Within a day5 outcomes, 2 as a primary outcome
Up to 4 weeks13 outcomes, 5 as a primary outcome
1 to 3 months14 outcomes, 4 as a primary outcome
3 to 6 months17 outcomes, 5 as a primary outcome
6 to 12 months4 outcomes, 1 as a primary outcome
1 to 2 years2 outcomes, 1 as a primary outcome
Over 2 years3 outcomes, 3 as a primary outcome
No duration given5 outcomes, 2 as a primary outcome

A test as a primary outcomeOnly in secondary or other outcomes

58 of the 63 outcome measures give a duration. A single visit counts as within a day.

Status, results, interventions and countries

Status

Recruiting18 studies, 10 as a primary outcome
Not yet recruiting8 studies, 4 as a primary outcome
Active, not recruiting1 studies, 1 as a primary outcome
Completed28 studies, 6 as a primary outcome
Status unknown8 studies, 2 as a primary outcome

What they test

Behavioral23 studies, 5 as a primary outcome
Drug4 studies, 0 as a primary outcome
Device17 studies, 7 as a primary outcome
Dietary supplement5 studies, 3 as a primary outcome
Diagnostic test1 studies, 1 as a primary outcome
Combination product1 studies, 1 as a primary outcome
Other13 studies, 6 as a primary outcome
None given3 studies, 3 as a primary outcome

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

24 countries in all. A study with sites in several counts in each; 5 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 sleep and sleep disorders studies that name the Digit Span Test: 13 of 28, 46%

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

Completed sleep and sleep disorders studies that name the Digit Span Test and every completed study, by how they reported results
Results	Completed sleep and sleep disorders studies that name the Digit Span Test	Every completed study
Results on ClinicalTrials.gov and a paper	4, 14%	776, 10%
Results on ClinicalTrials.gov only	2, 7%	1,139, 14%
A results paper only	7, 25%	1,711, 22%
Neither	15, 54%	4,327, 54%

The 63 studies

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

63 studies match. 23 name the Digit Span Test in a primary outcome. Median size 80 participants. Median time to the primary outcome: 8 weeks.

Loading 63 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	0	0
2004	1	0
2005	0	0
2006	0	0
2007	0	0
2008	0	0
2009	0	0
2010	2	1
2011	2	0
2012	2	0
2013	1	0
2014	1	0
2015	0	0
2016	1	1
2017	3	0
2018	3	1
2019	6	1
2020	5	3
2021	2	1
2022	2	0
2023	5	1
2024	9	5
2025	9	5
2026	9	4

Library tests named most

Largest condition groups

Sleep and sleep disorders63 studies, 23 as a primary outcome
Depression and bipolar disorder12 studies, 8 as a primary outcome
Anxiety, PTSD and OCD8 studies, 4 as a primary outcome
Cancer7 studies, 4 as a primary outcome
Pain and fatigue7 studies, 5 as a primary outcome
Mild cognitive impairment4 studies, 3 as a primary outcome
Healthy volunteers4 studies, 0 as a primary outcome
Aging, frailty and exercise4 studies, 4 as a primary outcome
Cardiovascular disease4 studies, 2 as a primary outcome
Dementia and Alzheimer's3 studies, 2 as a primary outcome
ADHD2 studies, 0 as a primary outcome
Parkinson's disease1 study, 0 as a primary outcome

Phases

Participants

Lead sponsor: industry 4, other 59. Interventional 55, observational 8.

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
NCT07897474	Start2026	PhaseObservational	ConditionsSleep and sleep disorders	Participants100	Lead sponsorOther	StatusNot yet recruiting	Library tests named Trail Making TestPrimary Stroop Color-Word TestPrimary Digit Span TestPrimary Symbol CodingPrimary Psychomotor Vigilance TaskPrimary
NCT07882433	Start2026	PhaseNot applicable	ConditionsSleep and sleep disorders	Participants50	Lead sponsorOther	StatusNot yet recruiting	Library tests named Trail Making TestSecondary6 months Stroop Color-Word TestSecondary6 months Verbal FluencySecondary6 months Digit Span TestSecondary6 months Paced Visual Serial Addition TestSecondary6 months
NCT07799753	Start2026	PhaseNot applicable	ConditionsSleep and sleep disorders	Participants50	Lead sponsorOther	StatusNot yet recruiting	Library tests named Trail Making TestSecondary4 weeks Stroop Color-Word TestSecondary4 weeks Digit Span TestSecondary4 weeks Symbol CodingSecondary4 weeks
NCT07767617	Start2026	PhaseNot applicable	ConditionsADHD, Sleep and sleep disorders	Participants150	Lead sponsorOther	StatusNot yet recruiting	Library tests named Digit Span TestSecondary6 months Go/No-Go TaskSecondary4 weeks Continuous Performance TestSecondary6 months Stop-Signal TaskSecondary4 weeks Delay DiscountingSecondary6 months AX Continuous Performance TestWording unclear Balloon RiskSecondary4 weeks Beads TaskSecondary6 months
NCT07740967	Start2026	PhaseNot applicable	ConditionsSleep and sleep disorders, Pain and fatigue, Cardiovascular disease	Participants34	Lead sponsorOther	StatusRecruiting	Library tests named Stroop Color-Word TestSecondary8 weeks Digit Span TestSecondary8 weeks Pattern and Letter ComparisonSecondary8 weeks
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
NCT07729930	Start2026	PhaseNot applicable	ConditionsSleep and sleep disorders, Pain and fatigue, Cardiovascular disease	Participants38	Lead sponsorOther	StatusRecruiting	Library tests named Stroop Color-Word TestPrimary8 weeks Digit Span TestPrimary8 weeks Pattern and Letter ComparisonPrimary8 weeks
NCT07659171	Start2019	PhaseNot applicable	ConditionsDepression and bipolar disorder, Sleep and sleep disorders, Anxiety, PTSD and OCD	Participants39	Lead sponsorOther	StatusCompleted	Library tests named Digit Span TestSecondary3 weeks Operation SpanSecondary3 weeks
NCT07608614	Start2025	PhaseNot applicable	ConditionsSleep and sleep disorders	Participants16	Lead sponsorOther	StatusRecruiting	Library tests named Digit Span TestSecondary Symbol CodingSecondary Go/No-Go TaskSecondary Psychomotor Vigilance TaskSecondary
NCT07364318	Start2024	PhaseObservational	ConditionsSleep and sleep disorders	Participants30	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestPrimarysame day Stroop Color-Word TestPrimarysame day Verbal LearningPrimarysame day Verbal FluencyPrimarysame day Digit Span TestPrimarysame day Category FluencyPrimarysame day Task Switching TestPrimarysame day
NCT07355842	Start2026	PhaseNot applicable	ConditionsParkinson's disease, Sleep and sleep disorders	Participants80	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestSecondary18 months Stroop Color-Word TestSecondary18 months Verbal LearningSecondary18 months Verbal FluencySecondary18 months Digit Span TestSecondary18 months Category FluencySecondary18 months Picture Naming TestSecondary18 months Psychomotor Vigilance TaskOther outcome18 months Complex Figure Copy and RecallSecondary18 months Finger Tapping TaskSecondary18 months Sustained Attention to ResponseOther outcome18 months Line Angle MatchingSecondary18 months
NCT07329049	Start2026	PhaseNot applicable	ConditionsSleep and sleep disorders	Participants42	Lead sponsorOther	StatusNot yet recruiting	Library tests named Stroop Color-Word TestPrimary8 weeks Verbal FluencyPrimary8 weeks Digit Span TestPrimary8 weeks
NCT07319117	Start2025	PhaseNot applicable	ConditionsDepression and bipolar disorder, Sleep and sleep disorders, Anxiety, PTSD and OCD, Pain and fatigue, Cardiovascular disease	Participants40	Lead sponsorOther	StatusRecruiting	Library tests named Digit Span TestPrimary Stop-Signal TaskPrimary Rapid Visual Information ProcessingPrimary Intra/Extra Dimensional Set ShiftPrimary
NCT07258433	Start2025	PhaseNot applicable	ConditionsHealthy volunteers, Sleep and sleep disorders	Participants120	Lead sponsorIndustry	StatusCompleted	Library tests named Digit Span TestSecondary6 weeks
NCT07236229	Start2025	PhaseNot applicable	ConditionsSleep and sleep disorders, Pain and fatigue	Participants34	Lead sponsorOther	StatusCompleted	Library tests named Digit Span TestSecondary6 weeks Card Sorting Test (Berg)Secondary6 weeks
NCT07156708	Start2025	PhaseNot applicable	ConditionsAging, frailty and exercise, Sleep and sleep disorders	Participants98	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestSecondary6 months Stroop Color-Word TestSecondary13 weeks Verbal FluencyPrimary6 months Digit Span TestPrimary6 months
NCT07084701	Start2025	PhaseNot applicable	ConditionsSleep and sleep disorders	Participants30	Lead sponsorOther	StatusRecruiting	Library tests named Digit Span TestPrimary2 weeks N-Back TaskSecondary2 weeks Psychomotor Vigilance TaskSecondary2 weeks
NCT07064382	Start2025	PhaseNot applicable	ConditionsDementia and Alzheimer's, Sleep and sleep disorders	Participants60	Lead sponsorOther	StatusNot yet recruiting	Library tests named Digit Span TestPrimary3 years Mental RotationPrimary3 years Route Directions Task and Which-Way-Back GamePrimary3 years
NCT06773416	Start2025	PhaseNot applicable	ConditionsMild cognitive impairment, Aging, frailty and exercise, Sleep and sleep disorders	Participants206	Lead sponsorOther	StatusNot yet recruiting	Library tests named Trail Making TestPrimary7 months Verbal LearningPrimary7 months Digit Span TestPrimary7 months Symbol CodingPrimary7 months Letter-Number Sequencing TaskPrimary7 months
NCT06710652	Start2025	PhaseNot applicable	ConditionsSleep and sleep disorders	Participants66	Lead sponsorOther	StatusNot yet recruiting	Library tests named Verbal LearningSecondary2 weeks Digit Span TestSecondary2 weeks
NCT06553235	Start2024	PhaseNot applicable	ConditionsCancer, Sleep and sleep disorders	Participants84	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestSecondary8 months Stroop Color-Word TestSecondary8 months Verbal LearningSecondary8 months Verbal FluencySecondary8 months Digit Span TestSecondary8 months Symbol CodingSecondary8 months Continuous Performance TestPrimary8 months Psychomotor Vigilance TaskSecondary8 months Paced Visual Serial Addition TestSecondary8 months
NCT06411561	Start2024	PhaseNot applicable	ConditionsDementia and Alzheimer's, Sleep and sleep disorders, Delirium, surgery and intensive care	Participants100	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestSecondary1 week Digit Span TestSecondary1 week
NCT06363981	Start2024	PhaseNot applicable	ConditionsDepression and bipolar disorder, Sleep and sleep disorders	Participants90	Lead sponsorOther	StatusRecruiting	Library tests named Digit Span TestPrimary4 weeks
NCT06348810	Start2024	PhaseNot applicable	ConditionsDementia and Alzheimer's, Mild cognitive impairment, Aging, frailty and exercise, Sleep and sleep disorders	Participants72	Lead sponsorOther	StatusStatus unknown	Library tests named Digit Span TestPrimary16 weeks Card Sorting Test (Berg)Primary16 weeks
NCT06335784	Start2024	PhaseNot applicable	ConditionsSleep and sleep disorders	Participants120	Lead sponsorOther	StatusRecruiting	Library tests named Digit Span TestOther outcome5 weeks Psychomotor Vigilance TaskOther outcome5 weeks Paired Associate LearningOther outcome5 weeks

Questions, answered from the data

How many sleep trials use the Digit Span Test?

63 registered sleep and sleep disorders studies on ClinicalTrials.gov name it in an outcome measure, 23 of them in a primary outcome: 8% of the condition's 749 studies with a cognitive outcome, against 10% of all of them. It is the 6th most named test in sleep trials.

Which tests do sleep trials use with the Digit Span Test?

The Trail Making Test (24 studies), the Stroop Color-Word Test (23 studies) and Verbal Fluency (18 studies).

When do sleep trials measure the Digit Span Test?

Half of the primary outcomes that name the Digit Span Test are measured within 8 weeks of the start, and the middle half from 2 weeks to 6 months. 21 primary outcomes give a duration.

How many completed sleep trials that use the Digit Span Test have reported results?

13 of the 28 completed studies that name it, 46%, have reported results: 6 posted them on ClinicalTrials.gov, 11 have a results paper linked to the registry record, and 4 did both. The other 15 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 sleep trials: 63 registered studies

Registered sleep and sleep disorders studies name it in an outcome measure: 63
Name it in a primary outcome, 37%: 23 of 63
Of the condition's 749 studies name it, against 10% of all registered studies: 8%; Other conditions
Median participants per study: 80; By phase

Try the Digit Span Test

Tests named in the same studies

The library tests that sleep and sleep disorders studies naming the Digit Span Test name most often beside it.

1
Trail Making Test24 studies, 7 as a primary outcome
2
Stroop Color-Word Test23 studies, 9 as a primary outcome
3
Verbal Fluency18 studies, 7 as a primary outcome
4
Verbal Learning17 studies, 5 as a primary outcome
5
Psychomotor Vigilance Task13 studies, 3 as a primary outcome
6
Symbol Coding11 studies, 4 as a primary outcome
7
N-Back Task10 studies, 2 as a primary outcome
8
Card Sorting Test (Berg)9 studies, 1 as a primary outcome
9
Go/No-Go Task9 studies, 1 as a primary outcome
10
Balloon Risk7 studies, 0 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	0	0
2004	1	0
2005	0	0
2006	0	0
2007	0	0
2008	0	0
2009	0	0
2010	2	1
2011	2	0
2012	2	0
2013	1	0
2014	1	0
2015	0	0
2016	1	1
2017	3	0
2018	3	1
2019	6	1
2020	5	3
2021	2	1
2022	2	0
2023	5	1
2024	9	5
2025	9	5
2026	9	4

Phases and study sizes

By phase

Phase 11 studies, 0 as a primary outcome
Phase 22 studies, 1 as a primary outcome
Phase 32 studies, 0 as a primary outcome
Phase 42 studies, 0 as a primary outcome
Not applicable48 studies, 18 as a primary outcome
Observational8 studies, 4 as a primary outcome

Participants per study

Not applicable70 median, 40 to 132

Show as a table

Participants per sleep and sleep disorders study that names the Digit Span Test, by phase
Phase	Studies with a size	Median	Middle half
Not applicable	48	70	40 to 132

When sleep trials measure it

Half of the primary outcomes that name the Digit Span Test are measured within 8 weeks of the start, and the middle half from 2 weeks to 6 months. 21 primary outcomes give a duration.

Latest time point of each outcome

Within a day5 outcomes, 2 as a primary outcome
Up to 4 weeks13 outcomes, 5 as a primary outcome
1 to 3 months14 outcomes, 4 as a primary outcome
3 to 6 months17 outcomes, 5 as a primary outcome
6 to 12 months4 outcomes, 1 as a primary outcome
1 to 2 years2 outcomes, 1 as a primary outcome
Over 2 years3 outcomes, 3 as a primary outcome
No duration given5 outcomes, 2 as a primary outcome

A test as a primary outcomeOnly in secondary or other outcomes

58 of the 63 outcome measures give a duration. A single visit counts as within a day.

Status, results, interventions and countries

Status

Recruiting18 studies, 10 as a primary outcome
Not yet recruiting8 studies, 4 as a primary outcome
Active, not recruiting1 studies, 1 as a primary outcome
Completed28 studies, 6 as a primary outcome
Status unknown8 studies, 2 as a primary outcome

What they test

Behavioral23 studies, 5 as a primary outcome
Drug4 studies, 0 as a primary outcome
Device17 studies, 7 as a primary outcome
Dietary supplement5 studies, 3 as a primary outcome
Diagnostic test1 studies, 1 as a primary outcome
Combination product1 studies, 1 as a primary outcome
Other13 studies, 6 as a primary outcome
None given3 studies, 3 as a primary outcome

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

24 countries in all. A study with sites in several counts in each; 5 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 sleep and sleep disorders studies that name the Digit Span Test: 13 of 28, 46%

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

Completed sleep and sleep disorders studies that name the Digit Span Test and every completed study, by how they reported results
Results	Completed sleep and sleep disorders studies that name the Digit Span Test	Every completed study
Results on ClinicalTrials.gov and a paper	4, 14%	776, 10%
Results on ClinicalTrials.gov only	2, 7%	1,139, 14%
A results paper only	7, 25%	1,711, 22%
Neither	15, 54%	4,327, 54%

The 63 studies

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

63 studies match. 23 name the Digit Span Test in a primary outcome. Median size 80 participants. Median time to the primary outcome: 8 weeks.

Loading 63 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	0	0
2004	1	0
2005	0	0
2006	0	0
2007	0	0
2008	0	0
2009	0	0
2010	2	1
2011	2	0
2012	2	0
2013	1	0
2014	1	0
2015	0	0
2016	1	1
2017	3	0
2018	3	1
2019	6	1
2020	5	3
2021	2	1
2022	2	0
2023	5	1
2024	9	5
2025	9	5
2026	9	4

Library tests named most

Largest condition groups

Sleep and sleep disorders63 studies, 23 as a primary outcome
Depression and bipolar disorder12 studies, 8 as a primary outcome
Anxiety, PTSD and OCD8 studies, 4 as a primary outcome
Cancer7 studies, 4 as a primary outcome
Pain and fatigue7 studies, 5 as a primary outcome
Mild cognitive impairment4 studies, 3 as a primary outcome
Healthy volunteers4 studies, 0 as a primary outcome
Aging, frailty and exercise4 studies, 4 as a primary outcome
Cardiovascular disease4 studies, 2 as a primary outcome
Dementia and Alzheimer's3 studies, 2 as a primary outcome
ADHD2 studies, 0 as a primary outcome
Parkinson's disease1 study, 0 as a primary outcome

Phases

Participants

Lead sponsor: industry 4, other 59. Interventional 55, observational 8.

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
NCT07897474	Start2026	PhaseObservational	ConditionsSleep and sleep disorders	Participants100	Lead sponsorOther	StatusNot yet recruiting	Library tests named Trail Making TestPrimary Stroop Color-Word TestPrimary Digit Span TestPrimary Symbol CodingPrimary Psychomotor Vigilance TaskPrimary
NCT07882433	Start2026	PhaseNot applicable	ConditionsSleep and sleep disorders	Participants50	Lead sponsorOther	StatusNot yet recruiting	Library tests named Trail Making TestSecondary6 months Stroop Color-Word TestSecondary6 months Verbal FluencySecondary6 months Digit Span TestSecondary6 months Paced Visual Serial Addition TestSecondary6 months
NCT07799753	Start2026	PhaseNot applicable	ConditionsSleep and sleep disorders	Participants50	Lead sponsorOther	StatusNot yet recruiting	Library tests named Trail Making TestSecondary4 weeks Stroop Color-Word TestSecondary4 weeks Digit Span TestSecondary4 weeks Symbol CodingSecondary4 weeks
NCT07767617	Start2026	PhaseNot applicable	ConditionsADHD, Sleep and sleep disorders	Participants150	Lead sponsorOther	StatusNot yet recruiting	Library tests named Digit Span TestSecondary6 months Go/No-Go TaskSecondary4 weeks Continuous Performance TestSecondary6 months Stop-Signal TaskSecondary4 weeks Delay DiscountingSecondary6 months AX Continuous Performance TestWording unclear Balloon RiskSecondary4 weeks Beads TaskSecondary6 months
NCT07740967	Start2026	PhaseNot applicable	ConditionsSleep and sleep disorders, Pain and fatigue, Cardiovascular disease	Participants34	Lead sponsorOther	StatusRecruiting	Library tests named Stroop Color-Word TestSecondary8 weeks Digit Span TestSecondary8 weeks Pattern and Letter ComparisonSecondary8 weeks
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
NCT07729930	Start2026	PhaseNot applicable	ConditionsSleep and sleep disorders, Pain and fatigue, Cardiovascular disease	Participants38	Lead sponsorOther	StatusRecruiting	Library tests named Stroop Color-Word TestPrimary8 weeks Digit Span TestPrimary8 weeks Pattern and Letter ComparisonPrimary8 weeks
NCT07659171	Start2019	PhaseNot applicable	ConditionsDepression and bipolar disorder, Sleep and sleep disorders, Anxiety, PTSD and OCD	Participants39	Lead sponsorOther	StatusCompleted	Library tests named Digit Span TestSecondary3 weeks Operation SpanSecondary3 weeks
NCT07608614	Start2025	PhaseNot applicable	ConditionsSleep and sleep disorders	Participants16	Lead sponsorOther	StatusRecruiting	Library tests named Digit Span TestSecondary Symbol CodingSecondary Go/No-Go TaskSecondary Psychomotor Vigilance TaskSecondary
NCT07364318	Start2024	PhaseObservational	ConditionsSleep and sleep disorders	Participants30	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestPrimarysame day Stroop Color-Word TestPrimarysame day Verbal LearningPrimarysame day Verbal FluencyPrimarysame day Digit Span TestPrimarysame day Category FluencyPrimarysame day Task Switching TestPrimarysame day
NCT07355842	Start2026	PhaseNot applicable	ConditionsParkinson's disease, Sleep and sleep disorders	Participants80	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestSecondary18 months Stroop Color-Word TestSecondary18 months Verbal LearningSecondary18 months Verbal FluencySecondary18 months Digit Span TestSecondary18 months Category FluencySecondary18 months Picture Naming TestSecondary18 months Psychomotor Vigilance TaskOther outcome18 months Complex Figure Copy and RecallSecondary18 months Finger Tapping TaskSecondary18 months Sustained Attention to ResponseOther outcome18 months Line Angle MatchingSecondary18 months
NCT07329049	Start2026	PhaseNot applicable	ConditionsSleep and sleep disorders	Participants42	Lead sponsorOther	StatusNot yet recruiting	Library tests named Stroop Color-Word TestPrimary8 weeks Verbal FluencyPrimary8 weeks Digit Span TestPrimary8 weeks
NCT07319117	Start2025	PhaseNot applicable	ConditionsDepression and bipolar disorder, Sleep and sleep disorders, Anxiety, PTSD and OCD, Pain and fatigue, Cardiovascular disease	Participants40	Lead sponsorOther	StatusRecruiting	Library tests named Digit Span TestPrimary Stop-Signal TaskPrimary Rapid Visual Information ProcessingPrimary Intra/Extra Dimensional Set ShiftPrimary
NCT07258433	Start2025	PhaseNot applicable	ConditionsHealthy volunteers, Sleep and sleep disorders	Participants120	Lead sponsorIndustry	StatusCompleted	Library tests named Digit Span TestSecondary6 weeks
NCT07236229	Start2025	PhaseNot applicable	ConditionsSleep and sleep disorders, Pain and fatigue	Participants34	Lead sponsorOther	StatusCompleted	Library tests named Digit Span TestSecondary6 weeks Card Sorting Test (Berg)Secondary6 weeks
NCT07156708	Start2025	PhaseNot applicable	ConditionsAging, frailty and exercise, Sleep and sleep disorders	Participants98	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestSecondary6 months Stroop Color-Word TestSecondary13 weeks Verbal FluencyPrimary6 months Digit Span TestPrimary6 months
NCT07084701	Start2025	PhaseNot applicable	ConditionsSleep and sleep disorders	Participants30	Lead sponsorOther	StatusRecruiting	Library tests named Digit Span TestPrimary2 weeks N-Back TaskSecondary2 weeks Psychomotor Vigilance TaskSecondary2 weeks
NCT07064382	Start2025	PhaseNot applicable	ConditionsDementia and Alzheimer's, Sleep and sleep disorders	Participants60	Lead sponsorOther	StatusNot yet recruiting	Library tests named Digit Span TestPrimary3 years Mental RotationPrimary3 years Route Directions Task and Which-Way-Back GamePrimary3 years
NCT06773416	Start2025	PhaseNot applicable	ConditionsMild cognitive impairment, Aging, frailty and exercise, Sleep and sleep disorders	Participants206	Lead sponsorOther	StatusNot yet recruiting	Library tests named Trail Making TestPrimary7 months Verbal LearningPrimary7 months Digit Span TestPrimary7 months Symbol CodingPrimary7 months Letter-Number Sequencing TaskPrimary7 months
NCT06710652	Start2025	PhaseNot applicable	ConditionsSleep and sleep disorders	Participants66	Lead sponsorOther	StatusNot yet recruiting	Library tests named Verbal LearningSecondary2 weeks Digit Span TestSecondary2 weeks
NCT06553235	Start2024	PhaseNot applicable	ConditionsCancer, Sleep and sleep disorders	Participants84	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestSecondary8 months Stroop Color-Word TestSecondary8 months Verbal LearningSecondary8 months Verbal FluencySecondary8 months Digit Span TestSecondary8 months Symbol CodingSecondary8 months Continuous Performance TestPrimary8 months Psychomotor Vigilance TaskSecondary8 months Paced Visual Serial Addition TestSecondary8 months
NCT06411561	Start2024	PhaseNot applicable	ConditionsDementia and Alzheimer's, Sleep and sleep disorders, Delirium, surgery and intensive care	Participants100	Lead sponsorOther	StatusRecruiting	Library tests named Trail Making TestSecondary1 week Digit Span TestSecondary1 week
NCT06363981	Start2024	PhaseNot applicable	ConditionsDepression and bipolar disorder, Sleep and sleep disorders	Participants90	Lead sponsorOther	StatusRecruiting	Library tests named Digit Span TestPrimary4 weeks
NCT06348810	Start2024	PhaseNot applicable	ConditionsDementia and Alzheimer's, Mild cognitive impairment, Aging, frailty and exercise, Sleep and sleep disorders	Participants72	Lead sponsorOther	StatusStatus unknown	Library tests named Digit Span TestPrimary16 weeks Card Sorting Test (Berg)Primary16 weeks
NCT06335784	Start2024	PhaseNot applicable	ConditionsSleep and sleep disorders	Participants120	Lead sponsorOther	StatusRecruiting	Library tests named Digit Span TestOther outcome5 weeks Psychomotor Vigilance TaskOther outcome5 weeks Paired Associate LearningOther outcome5 weeks

Questions, answered from the data

How many sleep trials use the Digit Span Test?

Which tests do sleep trials use with the Digit Span Test?

The Trail Making Test (24 studies), the Stroop Color-Word Test (23 studies) and Verbal Fluency (18 studies).

When do sleep trials measure the Digit Span Test?

Half of the primary outcomes that name the Digit Span Test are measured within 8 weeks of the start, and the middle half from 2 weeks to 6 months. 21 primary outcomes give a duration.

How many completed sleep 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 sleep trials: 63 registered studies

Tests named in the same studies

Studies by start year

Phases and study sizes

By phase

Participants per study

When sleep 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 63 studies

Library tests named most

Largest condition groups

Phases

Participants

The studies, newest registration first

Questions, answered from the data

How many sleep trials use the Digit Span Test?

Which tests do sleep trials use with the Digit Span Test?

When do sleep trials measure the Digit Span Test?

How many completed sleep trials that use the Digit Span Test have reported results?

More on the Digit Span Test and sleep and sleep disorders

The Digit Span Test in other conditions

Other tests in sleep trials

How the studies are counted

Run the Digit Span Test in your trial

Digit Span Test in sleep trials: 63 registered studies

Tests named in the same studies

Studies by start year

Phases and study sizes

By phase

Participants per study

When sleep 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 63 studies

Library tests named most

Largest condition groups

Phases

Participants

The studies, newest registration first

Questions, answered from the data

How many sleep trials use the Digit Span Test?

Which tests do sleep trials use with the Digit Span Test?

When do sleep trials measure the Digit Span Test?

How many completed sleep trials that use the Digit Span Test have reported results?

More on the Digit Span Test and sleep and sleep disorders

The Digit Span Test in other conditions

Other tests in sleep trials

How the studies are counted

Run the Digit Span Test in your trial