ConductCognition

  • Domains

    Tests

    • Processing speed43
    • Attention113
    • Working memory50
    • Executive function143
    • Episodic memory72
    • Response inhibition9
    • Social cognition75
    • Language42

    Most used

    Evidence

    1. Verbal Fluency TestGradeA
    2. Stroop Color-Word TestGradeA
    3. Trail Making TestGradeA
    4. N-Back TaskGradeA
    5. Go/No-Go TaskGradeA
    6. Digit Span TestGradeA
    7. Symbol Coding TestGradeA
    8. Verbal Learning TestGradeA
    REDTry it nowStroop Color-Word Test
    All 547 tests

    Browse by

    • Phone290
    • Tablet323
    • Untimed326
    • Up to 5 minutes69
    • Evidence grade A40

  • First studies

    Grade, length

    • Reaction Time StudyGradeA7 min
    • Pilot ScreeningGradeA15 min
    • Medication StudiesGradeA−26 min
    • Language-Minimized ScreeningGradeA−30 min

    Age groups

    • Older Adult Executive SpeedGradeA20 min
    • School-AgeGradeA−33 min

    Memory

    • At-Home MemoryGradeA26 min
    • Working Memory and LearningGradeA−19 min
    • Associative MemoryGradeB32 min
    • Working Memory CapacityGradeB34 min

    Language and perception

    • LanguageGradeA−33 min
    • Visual PerceptionGradeB27 min
    • Listening and Auditory ProcessingGradeB31 min

    Executive function and attention

    • Executive ControlGradeA18 min
    • Attention and ImpulsivityGradeA−26 min
    • Visual AttentionGradeB27 min
    • Creativity and Flexible ThinkingGradeB30 min
    • Reasoning and SpatialGradeB32 min

    Movement

    • Motor and AttentionGradeA−29 min
    • Motor LearningGradeB34 min

    Behavior, mood and choice

    • Food Choice and Self-ControlGradeA−29 min
    • Sleep and FatigueGradeB23 min
    • Social CognitionGradeB23 min
    • Impulsivity and Substance UseGradeB26 min
    • Emotion and MoodGradeB28 min
    • Decisions and RewardGradeB29 min
    All 26 batteries

    Find one

    Up to 15 minutes2Up to 30 minutes19Phone8
    Test order labBattery gradesHow batteries work

  • Use and evidence

    • Overview
    • Compare all 547 tests
    • Test-retest
    • Reliability and validity
    • Battery grades26
    • Download and cite

    Clinical trials

    • Overview
    • By condition25
    • By test101
    • Trial design benchmark
    • Cognitive outcomes, 2026

    Conditions

    Registered studies

    • Dementia and Alzheimer's1,673
    • Aging, frailty and exercise1,398
    • Depression and bipolar disorder1,247
    • Stroke1,233
    • Substance use and addiction895
    • Parkinson's disease892
    • Cancer760
    All 25 conditions
    16,361Registered studies name a cognitive test in an outcome measure11,688 name a test you can run hereExplore the studies
  • 1

    Build

    • Study design
    • Customize tests
    • Repeat visits
    • Study cost calculator
    2

    Recruit

    • Recruitment setup
    • Prolific
    • Sona Systems
    • CloudResearch Connect
    • Qualtrics
    3

    Run

    • Remote testing
    • Participant devices
    • Phone timing check
    • Offline edition
    4

    Results

    • Automated scoring
    • Test norms
    • Study Quality Monitor
    • Data export
    Platform overview

    Compliance

    • HIPAA-ready testing
    • US clinical research
    • Data Policy
    • Privacy Policy
    • Terms of Use

  • Research areas

    Tests used in each

    • Aging and dementia188
    • Decisions and reward105
    • Child development and education87
    • Language and bilingualism64
    • Social behavior62
    • Psychiatric groups35
    • Training and intervention28
    • Mood, anxiety and trauma25
    • Substance use and impulsivity25
    • Neurological and movement research19
    • Brain injury and concussion14
    • Sleep and fatigue14
    • ADHD11
    • Eating and obesity8
    • Medication and drug trials8

    Research settings

    • Student participant pools
    • Teaching a class
    • Clinical trials
    • US clinical research
    • Sites without internet
    Planning a study?

  • Methods

    • How evidence grades work
    • How test batteries work
    • How test order works
    Methods and questions

    Help

    • FAQ
    • Recruitment guides
    • Compare platforms

    Updates

    • Blog
    • New tests by email
    Latest post10 November 2026What you can do in ConductCognition todayA short tour of ConductCognition as it stands on 10 November. After this, we'll post when something changes how you run a study.Read the post
  • Pricing
Start Free
Log In
Log InStart Free
  1. Home
  2. /Data
  3. /Clinical trials
  4. /Conditions
  5. /Parkinson's disease
  6. /Digit Span Test

Clinical trials data

Digit Span Test in Parkinson's disease trials: 86 registered studies

Every registered Parkinson's disease 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 Parkinson's disease studies name it in an outcome measure
86
Name it in a primary outcome, 17%
15 of 86
Of the condition's 892 studies name it, against 10% of all registered studies
10%
Other conditions
Median participants per study
40
By phase
Try the Digit Span Test

Tests named in the same studies

The library tests that Parkinson's disease studies naming the Digit Span Test name most often beside it.
  1. 1

    Verbal Fluency43 studies, 8 as a primary outcome

  2. 2

    Trail Making Test42 studies, 8 as a primary outcome

  3. 3

    Stroop Color-Word Test37 studies, 8 as a primary outcome

  4. 4

    Verbal Learning21 studies, 5 as a primary outcome

  5. 5

    Category Fluency18 studies, 3 as a primary outcome

  6. 6

    Picture Naming Test14 studies, 3 as a primary outcome

  7. 7

    Line Angle Matching10 studies, 3 as a primary outcome

  8. 8

    Symbol Coding10 studies, 2 as a primary outcome

  9. 9

    Short Story Recall8 studies, 3 as a primary outcome

  10. 10

    Card Sorting Test (Berg)8 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.
02000: 0 studies, 0 with a test as a primary outcome20002001: 0 studies, 0 with a test as a primary outcome2002: 0 studies, 0 with a test as a primary outcome2003: 0 studies, 0 with a test as a primary outcome2004: 0 studies, 0 with a test as a primary outcome2005: 0 studies, 0 with a test as a primary outcome20052006: 0 studies, 0 with a test as a primary outcome2007: 1 studies, 0 with a test as a primary outcome2008: 0 studies, 0 with a test as a primary outcome2009: 1 studies, 0 with a test as a primary outcome2010: 1 studies, 0 with a test as a primary outcome20102011: 2 studies, 1 with a test as a primary outcome2012: 3 studies, 1 with a test as a primary outcome2013: 2 studies, 1 with a test as a primary outcome2014: 3 studies, 0 with a test as a primary outcome2015: 3 studies, 0 with a test as a primary outcome20152016: 2 studies, 0 with a test as a primary outcome2017: 6 studies, 0 with a test as a primary outcome2018: 7 studies, 1 with a test as a primary outcome2019: 7 studies, 1 with a test as a primary outcome2020: 7 studies, 2 with a test as a primary outcome20202021: 5 studies, 1 with a test as a primary outcome2022: 6 studies, 1 with a test as a primary outcome2023: 6 studies, 1 with a test as a primary outcome2024: 6 studies, 3 with a test as a primary outcome2025: 4 studies, 1 with a test as a primary outcome20252026: 14 studies, 1 with a test as a primary outcome

A test as a primary outcomeOnly in secondary or other outcomes

Show as a table
Registered studies by start year
Start yearStudiesA test as a primary outcome
200000
200100
200200
200300
200400
200500
200600
200710
200800
200910
201010
201121
201231
201321
201430
201530
201620
201760
201871
201971
202072
202151
202261
202361
202463
202541
2026141

Phases and study sizes

By phase

  • Early phase 12 studies, 0 as a primary outcome
  • Phase 12 studies, 0 as a primary outcome
  • Phase 1/23 studies, 1 as a primary outcome
  • Phase 26 studies, 0 as a primary outcome
  • Phase 31 studies, 1 as a primary outcome
  • Phase 42 studies, 0 as a primary outcome
  • Not applicable61 studies, 9 as a primary outcome
  • Observational9 studies, 4 as a primary outcome

Participants per study

102050100
  • Not applicable40 median, 25 to 66
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 Parkinson's disease study that names the Digit Span Test, by phase
PhaseStudies with a sizeMedianMiddle half
Not applicable614025 to 66

When Parkinson's disease trials measure it

Half of the primary outcomes that name the Digit Span Test are measured within 4 weeks of the start, and the middle half from 2 days to 4 months. 15 primary outcomes give a duration.

Latest time point of each outcome

  • Within a day13 outcomes, 4 as a primary outcome
  • Up to 4 weeks20 outcomes, 4 as a primary outcome
  • 1 to 3 months27 outcomes, 3 as a primary outcome
  • 3 to 6 months15 outcomes, 3 as a primary outcome
  • 6 to 12 months2 outcomes, 0 as a primary outcome
  • 1 to 2 years3 outcomes, 0 as a primary outcome
  • Over 2 years2 outcomes, 1 as a primary outcome
  • No duration given4 outcomes, 0 as a primary outcome

A test as a primary outcomeOnly in secondary or other outcomes

82 of the 86 outcome measures give a duration. A single visit counts as within a day.

Status, results, interventions and countries

Status

  • Recruiting19 studies, 5 as a primary outcome
  • Not yet recruiting4 studies, 1 as a primary outcome
  • Active, not recruiting3 studies, 0 as a primary outcome
  • Completed35 studies, 7 as a primary outcome
  • Stopped early4 studies, 0 as a primary outcome
  • Status unknown21 studies, 2 as a primary outcome

What they test

  • Behavioral24 studies, 4 as a primary outcome
  • Drug10 studies, 0 as a primary outcome
  • Device27 studies, 3 as a primary outcome
  • Procedure4 studies, 2 as a primary outcome
  • Diagnostic test3 studies, 0 as a primary outcome
  • Biological1 studies, 0 as a primary outcome
  • Radiation1 studies, 1 as a primary outcome
  • Genetic1 studies, 1 as a primary outcome
  • Other24 studies, 6 as a primary outcome
  • None given4 studies, 1 as a primary outcome

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

Where their sites are

  • United States22 studies, 2 as a primary outcome
  • Taiwan9 studies, 4 as a primary outcome
  • Türkiye6 studies, 3 as a primary outcome
  • China5 studies, 1 as a primary outcome
  • France5 studies, 0 as a primary outcome
  • Netherlands5 studies, 0 as a primary outcome
  • South Korea5 studies, 0 as a primary outcome
  • Brazil4 studies, 0 as a primary outcome
  • Switzerland4 studies, 1 as a primary outcome
  • Canada3 studies, 1 as a primary outcome
  • Sweden3 studies, 0 as a primary outcome
  • United Kingdom3 studies, 1 as a primary outcome

23 countries in all. A study with sites in several counts in each; 4 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 Parkinson's disease studies that name the Digit Span Test: 21 of 35, 60%

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

Completed Parkinson's disease studies that name the Digit Span Test and every completed study, by how they reported results
ResultsCompleted Parkinson's disease studies that name the Digit Span TestEvery completed study
Results on ClinicalTrials.gov and a paper6, 17%776, 10%
Results on ClinicalTrials.gov only6, 17%1,139, 14%
A results paper only9, 26%1,711, 22%
Neither14, 40%4,327, 54%

The 86 studies

Filter by phase, sponsor, status, country, intervention, outcome list, size and start year. Each study links to its record on ClinicalTrials.gov.
ConditionParkinson's disease
TestThe Digit Span Test

86 studies match. 15 name the Digit Span Test in a primary outcome. Median size 40 participants. Median time to the primary outcome: 4 weeks.

Loading 86 studies; the filters turn on when they arrive.

By start year
0510152000: 0 studies, 0 naming the Digit Span Test in a primary outcome20002001: 0 studies, 0 naming the Digit Span Test in a primary outcome2002: 0 studies, 0 naming the Digit Span Test in a primary outcome2003: 0 studies, 0 naming the Digit Span Test in a primary outcome2004: 0 studies, 0 naming the Digit Span Test in a primary outcome2005: 0 studies, 0 naming the Digit Span Test in a primary outcome20052006: 0 studies, 0 naming the Digit Span Test in a primary outcome2007: 1 studies, 0 naming the Digit Span Test in a primary outcome2008: 0 studies, 0 naming the Digit Span Test in a primary outcome2009: 1 studies, 0 naming the Digit Span Test in a primary outcome2010: 1 studies, 0 naming the Digit Span Test in a primary outcome20102011: 2 studies, 1 naming the Digit Span Test in a primary outcome2012: 3 studies, 1 naming the Digit Span Test in a primary outcome2013: 2 studies, 1 naming the Digit Span Test in a primary outcome2014: 3 studies, 0 naming the Digit Span Test in a primary outcome2015: 3 studies, 0 naming the Digit Span Test in a primary outcome20152016: 2 studies, 0 naming the Digit Span Test in a primary outcome2017: 6 studies, 0 naming the Digit Span Test in a primary outcome2018: 7 studies, 1 naming the Digit Span Test in a primary outcome2019: 7 studies, 1 naming the Digit Span Test in a primary outcome2020: 7 studies, 2 naming the Digit Span Test in a primary outcome20202021: 5 studies, 1 naming the Digit Span Test in a primary outcome2022: 6 studies, 1 naming the Digit Span Test in a primary outcome2023: 6 studies, 1 naming the Digit Span Test in a primary outcome2024: 6 studies, 3 naming the Digit Span Test in a primary outcome2025: 4 studies, 1 naming the Digit Span Test in a primary outcome20252026: 14 studies, 1 naming the Digit Span Test in a primary outcome

2026 is partly planned starts.

Show as a table
Matching studies by start year
Start yearStudiesAs a primary outcome
200000
200100
200200
200300
200400
200500
200600
200710
200800
200910
201010
201121
201231
201321
201430
201530
201620
201760
201871
201971
202072
202151
202261
202361
202463
202541
2026141

Library tests named most

  • Digit Span Test86 studies, 15 as a primary outcome
  • Verbal Fluency43 studies, 8 as a primary outcome
  • Trail Making Test42 studies, 8 as a primary outcome
  • Stroop Color-Word Test37 studies, 8 as a primary outcome
  • Verbal Learning21 studies, 5 as a primary outcome
  • Category Fluency18 studies, 3 as a primary outcome
  • Picture Naming Test14 studies, 3 as a primary outcome
  • Line Angle Matching10 studies, 3 as a primary outcome
  • Symbol Coding10 studies, 2 as a primary outcome
  • Short Story Recall8 studies, 3 as a primary outcome

Conditions

  • Parkinson's disease86 studies, 15 as a primary outcome
  • Dementia and Alzheimer's6 studies, 3 as a primary outcome
  • Depression and bipolar disorder5 studies, 1 as a primary outcome
  • Stroke4 studies, 0 as a primary outcome
  • Aging, frailty and exercise4 studies, 1 as a primary outcome
  • Mild cognitive impairment3 studies, 0 as a primary outcome
  • Healthy volunteers2 studies, 1 as a primary outcome
  • Multiple sclerosis1 study, 0 as a primary outcome
  • Obesity and diabetes1 study, 0 as a primary outcome
  • Sleep and sleep disorders1 study, 0 as a primary outcome
  • Cardiovascular disease1 study, 0 as a primary outcome
  • Lung disease1 study, 0 as a primary outcome

Phases

Participants

Lead sponsor: industry 2, other 84. Interventional 77, 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.
StudyStartPhaseConditionsParticipantsLead sponsorStatusLibrary tests named, with the latest time point
NCT07838675Start2026PhaseNot applicableConditionsParkinson's diseaseParticipants120Lead sponsorOtherStatusRecruitingLibrary tests named
  • Digit Span TestSecondary6 months
  • Word Pair LearningSecondary6 months
NCT07832695Start2026PhaseNot applicableConditionsParkinson's diseaseParticipants90Lead sponsorOtherStatusRecruitingLibrary tests named
  • Verbal FluencySecondary8 weeks
  • Digit Span TestSecondary8 weeks
NCT07813156Start2026PhaseNot applicableConditionsParkinson's diseaseParticipants24Lead sponsorOtherStatusNot yet recruitingLibrary tests named
  • Stroop Color-Word TestSecondary
  • Digit Span TestSecondary
  • Picture Naming TestSecondary
  • Clock Drawing TaskSecondary
  • Letter-Number Sequencing TaskSecondary
  • Selective Reminding TaskSecondary
  • Line Angle MatchingSecondary
NCT07678983Start2026PhaseNot applicableConditionsParkinson's diseaseParticipants66Lead sponsorOtherStatusActive, not recruitingLibrary tests named
  • Trail Making TestSecondary8 weeks
  • Stroop Color-Word TestSecondary8 weeks
  • Verbal FluencySecondary8 weeks
  • Digit Span TestSecondary8 weeks
  • Category FluencySecondary8 weeks
NCT07636538Start2026PhaseNot applicableConditionsMild cognitive impairment, Stroke, Parkinson's diseaseParticipants30Lead sponsorOtherStatusNot yet recruitingLibrary tests named
  • Trail Making TestSecondary
  • Stroop Color-Word TestSecondary
  • Digit Span TestSecondary
NCT07610369Start2026PhasePhase 2ConditionsParkinson's disease, Depression and bipolar disorderParticipants40Lead sponsorOtherStatusRecruitingLibrary tests named
  • Verbal LearningSecondary13 weeks
  • Digit Span TestSecondary13 weeks
  • Delay DiscountingSecondary13 weeks
  • Probabilistic Reversal LearningSecondary13 weeks
  • Simon TaskSecondary13 weeks
NCT07582497Start2026PhaseNot applicableConditionsStroke, Parkinson's diseaseParticipants60Lead sponsorOtherStatusNot yet recruitingLibrary tests named
  • Trail Making TestSecondary13 weeks
  • Digit Span TestSecondary13 weeks
  • Corsi Block-Tapping TestSecondary13 weeks
NCT07569120Start2026PhaseNot applicableConditionsParkinson's disease, Healthy volunteers, Aging, frailty and exerciseParticipants165Lead sponsorOtherStatusRecruitingLibrary tests named
  • Trail Making TestSecondary2 days
  • Verbal FluencySecondary2 days
  • Digit Span TestSecondary2 days
  • Category FluencySecondary2 days
  • Tower PlanningSecondary2 days
NCT07540325Start2026PhaseObservationalConditionsParkinson's diseaseParticipants30Lead sponsorOtherStatusNot yet recruitingLibrary tests named
  • Stroop Color-Word TestPrimarysame day
  • Verbal LearningPrimarysame day
  • Digit Span TestPrimarysame day
  • Picture Naming TestPrimarysame day
  • Line Angle MatchingPrimarysame day
NCT07536022Start2026PhaseNot applicableConditionsParkinson's diseaseParticipants16Lead sponsorOtherStatusRecruitingLibrary tests named
  • Stroop Color-Word TestOther outcome8 weeks
  • Verbal FluencyOther outcome8 weeks
  • Digit Span TestOther outcome8 weeks
NCT07518290Start2026PhaseNot applicableConditionsParkinson's diseaseParticipants98Lead sponsorOtherStatusRecruitingLibrary tests named
  • Trail Making TestSecondary4 weeks
  • Digit Span TestSecondary4 weeks
NCT07455760Start2026PhaseNot applicableConditionsParkinson's diseaseParticipants80Lead sponsorOtherStatusRecruitingLibrary tests named
  • Digit Span TestSecondarysame day
NCT07355842Start2026PhaseNot applicableConditionsParkinson's disease, Sleep and sleep disordersParticipants80Lead sponsorOtherStatusRecruitingLibrary 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
NCT07277205Start2026PhaseNot applicableConditionsParkinson's diseaseParticipants45Lead sponsorOtherStatusRecruitingLibrary tests named
  • Verbal FluencyPrimary8 weeks
  • Digit Span TestSecondary8 weeks
  • Category FluencyPrimary8 weeks
  • Clock Drawing TaskSecondary8 weeks
NCT07271927Start2025PhaseNot applicableConditionsParkinson's diseaseParticipants15Lead sponsorOtherStatusRecruitingLibrary tests named
  • Trail Making TestSecondary10 weeks
  • Stroop Color-Word TestSecondary10 weeks
  • Verbal LearningSecondary10 weeks
  • Digit Span TestSecondary10 weeks
  • Complex Figure Copy and RecallSecondary10 weeks
NCT07240272Start2023PhaseNot applicableConditionsParkinson's diseaseParticipants28Lead sponsorOtherStatusCompleted

Paper

Library tests named
  • Trail Making TestPrimary13 weeks
  • Verbal FluencyPrimary13 weeks
  • Digit Span TestPrimary13 weeks
  • Category FluencyPrimary13 weeks
NCT07058714Start2025PhaseObservationalConditionsParkinson's diseaseParticipants30Lead sponsorOtherStatusCompletedLibrary tests named
  • Verbal FluencySecondarysame day
  • Digit Span TestSecondarysame day
  • Arithmetic Fluency TaskSecondarysame day
NCT06782724Start2025PhasePhase 2ConditionsParkinson's disease, Multiple sclerosis, Depression and bipolar disorder, Lung diseaseParticipants108Lead sponsorOtherStatusRecruitingLibrary tests named
  • Trail Making TestOther outcome8 weeks
  • Verbal LearningOther outcome8 weeks
  • Verbal FluencyOther outcome8 weeks
  • Digit Span TestOther outcome8 weeks
  • Symbol CodingOther outcome8 weeks
NCT06588920Start2024PhaseObservationalConditionsParkinson's disease, Healthy volunteers, Aging, frailty and exerciseParticipants70Lead sponsorOtherStatusRecruitingLibrary tests named
  • Trail Making TestPrimarysame day
  • Stroop Color-Word TestPrimarysame day
  • Digit Span TestPrimarysame day
  • Go/No-Go TaskPrimarysame day
NCT06588439Start2025PhaseNot applicableConditionsParkinson's diseaseParticipants50Lead sponsorOtherStatusRecruitingLibrary tests named
  • Trail Making TestPrimary8 weeks
  • Stroop Color-Word TestPrimary8 weeks
  • Digit Span TestPrimary8 weeks
  • Go/No-Go TaskPrimary8 weeks
NCT06467695Start2024PhaseNot applicableConditionsParkinson's disease, Depression and bipolar disorderParticipants40Lead sponsorOtherStatusRecruitingLibrary tests named
  • Digit Span TestPrimary4 weeks
  • Short Story RecallPrimary4 weeks
NCT06416722Start2024PhaseNot applicableConditionsParkinson's diseaseParticipants30Lead sponsorOtherStatusRecruitingLibrary tests named
  • Verbal FluencyPrimary4 weeks
  • Digit Span TestPrimary4 weeks
NCT06399731Start2024PhaseNot applicableConditionsMild cognitive impairment, Parkinson's diseaseParticipants20Lead sponsorOtherStatusRecruitingLibrary tests named
  • Trail Making TestSecondary
  • Verbal LearningSecondary
  • Verbal FluencySecondary
  • Digit Span TestSecondary
  • Symbol CodingSecondary
  • Tower PlanningSecondary
  • Line Angle MatchingOther outcomesame day
NCT06350617Start2024PhaseNot applicableConditionsParkinson's diseaseParticipants60Lead sponsorOtherStatusRecruitingLibrary tests named
  • Trail Making TestSecondary4 weeks
  • Digit Span TestSecondary4 weeks
NCT06080659Start2023PhaseNot applicableConditionsDementia and Alzheimer's, Parkinson's diseaseParticipants120Lead sponsorOtherStatusRecruitingLibrary tests named
  • Digit Span TestSecondary6 months
  • Category FluencySecondary6 months
  • Picture Naming TestSecondary6 months
  • Clock Drawing TaskSecondary6 months
  • Letter-Number Sequencing TaskSecondary6 months
  • Selective Reminding TaskSecondary6 months
  • Line Angle MatchingSecondary6 months
  • Recognition Memory TestSecondary6 months

Page 1 of 4

Questions, answered from the data

How many Parkinson's disease trials use the Digit Span Test?

86 registered Parkinson's disease studies on ClinicalTrials.gov name it in an outcome measure, 15 of them in a primary outcome: 10% of the condition's 892 studies with a cognitive outcome, against 10% of all of them. It is the 4th most named test in Parkinson's disease trials.

Which tests do Parkinson's disease trials use with the Digit Span Test?

Verbal Fluency (43 studies), the Trail Making Test (42 studies) and the Stroop Color-Word Test (37 studies).

When do Parkinson's disease trials measure the Digit Span Test?

Half of the primary outcomes that name the Digit Span Test are measured within 4 weeks of the start, and the middle half from 2 days to 4 months. 15 primary outcomes give a duration.

How many completed Parkinson's disease trials that use the Digit Span Test have reported results?

21 of the 35 completed studies that name it, 60%, have reported results: 12 posted them on ClinicalTrials.gov, 15 have a results paper linked to the registry record, and 6 did both. The other 14 show neither. Of all completed studies with a cognitive outcome, 46% have reported results.

More on the Digit Span Test and Parkinson's disease

  • Every cognitive test in Parkinson's disease trials: 892 studies
  • The Digit Span Test in all clinical trials: 1,629 studies

The Digit Span Test in other conditions

  • Dementia and Alzheimer's181
  • Mild cognitive impairment169
  • Depression and bipolar disorder143
  • Aging, frailty and exercise129
  • Cancer107
  • Stroke100
  • Brain injury and concussion98
  • Anxiety, PTSD and OCD72
  • Schizophrenia and psychosis66
  • Healthy volunteers64
  • Obesity and diabetes64
  • Sleep and sleep disorders63
  • Pain and fatigue61
  • Cognitive impairment and decline60
  • Cardiovascular disease59
  • ADHD58

Other tests in Parkinson's disease trials

  • Trail Making Test156
  • Verbal Fluency140
  • Stroop Color-Word Test126
  • Verbal Learning61

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.

Run the Digit Span Test in your trial

Choose tests with a record in registered trials, and run them in a browser at every site, on the same version each visit.

Start free
ConductCognition

Hosted browser-native cognitive testing for academic and commercial research workflows.

A product of ConductScience, Inc.

New tests and features, about once a month. Unsubscribe at any time.

Tests

  • All cognitive tests
  • Test batteries
  • Use and evidence
  • Test norms
  • Trail Making Test
  • N-Back Task
  • Automated scoring
  • Study design
  • New tests by email

Guides

  • Methods and questions
  • Blog
  • Recruitment setup
  • Participant devices
  • Prolific
  • Sona Systems
  • CloudResearch Connect
  • Qualtrics

Use cases

  • Student participant pools
  • Aging and dementia research
  • Clinical trials
  • US clinical research
  • Remote testing

Compare and buy

  • Pricing
  • Compare platforms
  • Offline edition
  • FAQ

Trust

  • Study Quality Monitor
  • HIPAA-ready testing
  • Data export
  • Privacy Policy
  • Terms of Use
  • Data Policy

Company

  • ConductScience
  • Affiliate Program
© 2026 ConductScience, Inc. Research use only.