NCT07783074

Brief Summary

This study investigates objective methods to measure and monitor fatigue in patients with post-COVID-19 condition (long COVID) and multiple sclerosis (MS), and includes a group of healthy volunteers for comparison. Fatigue is a common and debilitating symptom of both conditions, but current assessment methods rely mainly on questionnaires, which can be limited by subjectivity and recall bias. The study uses a smartphone application (the FIDO app) together with wearable devices to continuously collect data on fatigue and its fluctuations during daily life, in order to evaluate the potential of digital, objective measures compared to standard assessments. Participation lasts approximately eight weeks and includes two in-person clinic visits along with a continuous data collection phase. At the initial visit, participants complete baseline assessments and questionnaires and are introduced to the study's digital tools. During the following weeks, participants wear two wearable devices continuously (24 hours a day) and use the FIDO app to complete short daily tasks (approximately 7 minutes every two days) and brief questionnaires (approximately 5 minutes per day). All participants collect a stool sample at home at weeks 4 and 8 for gut microbiome analysis, and complete the Fatigue Scale for Motor and Cognitive Functions at week 4. At the final study visit, participants repeat a subset of the baseline assessments, provide feedback on the digital technology used, and return the study devices.

Trial Health

77
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
122

participants targeted

Target at P50-P75 for all trials

Timeline
21mo left

Started May 2026

Geographic Reach
1 country

6 active sites

Status
recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Progress14%
May 2026May 2028

Study Start

First participant enrolled

May 26, 2026

Completed
3 months until next milestone

First Submitted

Initial submission to the registry

August 14, 2026

Completed
10 days until next milestone

First Posted

Study publicly available on registry

August 24, 2026

Completed
1.7 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

May 1, 2028

Expected
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

May 1, 2028

Last Updated

August 24, 2026

Status Verified

August 1, 2026

Enrollment Period

1.9 years

First QC Date

August 14, 2026

Last Update Submit

August 20, 2026

Conditions

Keywords

digital biomarkerwearable devicespassive sensingsmartphone applicationremote monitoringactigraphyheart rate variabilitylong COVIDPost-Acute COVID-19 Syndromefeasibility studycomplianceadherencefatigue monitoringgut microbiomepost-exertional malaisePEMMSFSMCfatiguefatigabilitymotor fatiguecognitive fatiguephysical fatiguesmartwatchActiGraph LEAPApple WatchGarminsmartphone

Outcome Measures

Primary Outcomes (4)

  • Percentage of Expected Smartwatch Wear Time Recorded Over Two Months

    Passive compliance with continuous smartwatch data collection, as a measure of feasibility of long-term fatigue monitoring. Participants wear a smartwatch continuously for two months: a Garmin smartwatch (multiple sclerosis group), an Apple Watch (post-COVID-19 condition group), or either device (healthy controls). Expected wear time is the full duration of each participant's individual enrolment (approximately 60 days), so the denominator is calculated per participant rather than as a fixed period; charging periods are not excluded, so values are not expected to reach 100%. Compliance is calculated per participant as recorded wear time divided by expected wear time, multiplied by 100. Values range from 0% to 100%, with higher values indicating greater compliance. Compliance is also compared by group, disease characteristics and demographic factors, and baseline characteristics associated with lower compliance are described.

    2 months

  • Percentage of Expected Armband Activity Monitor Wear Time Recorded Over Two Months

    Passive compliance with continuous armband data collection, as a measure of feasibility of long-term fatigue monitoring. Participants wear an armband activity monitor (ActiGraph LEAP) continuously for two months. All participants wear the same device, so compliance can be compared between groups independently of device type. Expected wear time is the full duration of each participant's individual enrolment (approximately 60 days), so the denominator is calculated per participant rather than as a fixed period; charging periods are not excluded, so values are not expected to reach 100%. Compliance is calculated per participant as recorded wear time divided by expected wear time, multiplied by 100. Values range from 0% to 100%, with higher values indicating greater compliance. Compliance is also compared by group, disease characteristics and demographic factors, and baseline characteristics associated with lower compliance are described.

    2 months

  • Percentage of Scheduled Study Application Questionnaires Completed Over Two Months

    Active compliance with self-reported data collection, as a measure of feasibility of long-term fatigue monitoring. Participants complete short questionnaires in the study smartphone application (FIDO app) over two months, comprising cognitive and motor fatigue visual analogue scales prompted four times daily at random times, morning and evening sleep surveys daily, and the Fatigue Severity Scale weekly in the multiple sclerosis and healthy control groups. The number scheduled follows each participant's individual enrolment (approximately 60 days). Compliance is calculated per participant as the number of questionnaires completed divided by the number scheduled, multiplied by 100. Values range from 0% to 100%, with higher values indicating greater compliance. Compliance is reported per questionnaire type, compared by group, disease characteristics and demographic factors, and baseline characteristics associated with lower compliance are described. Response latency is also evaluated.

    2 months

  • Percentage of Scheduled Study Application Performance Tasks Completed Over Two Months

    Active compliance with task-based data collection, as a measure of feasibility of long-term fatigue monitoring. Participants complete two brief performance tasks in the FIDO app approximately every second day over two months: a cognitive fatigability test (cFAST) and a 30-second finger tapping task, together taking approximately seven minutes. The number scheduled follows each participant's individual enrolment (approximately 60 days). Compliance is calculated per participant as the number of sessions completed divided by the number scheduled, multiplied by 100. A session counts as completed if the participant finishes the full task protocol. Values range from 0% to 100%, with higher values indicating greater compliance. Compliance is reported per task, compared by group, disease characteristics and demographic factors, and baseline characteristics associated with lower compliance are described. Response latency is also evaluated.

    2 months

Secondary Outcomes (23)

  • Discriminative Accuracy of Cognitive Fatigability Test and Finger Tapping Test Performance for Participant Group, Stratified by Fatigue Level

    2 months

  • Reliability and Within-Participant Variability of Cognitive Fatigability Test and Finger Tapping Test Performance

    2 months

  • Agreement Between Cognitive Fatigability Test and Finger Tapping Test Performance and Established Fatigue and Functional Assessments

    2 months

  • Association Between Digital Measurements Derived From Wearable Data and the Fatigue Scale for Motor and Cognitive Functions (FSMC)

    2 months

  • Discriminative Accuracy of Armband-Derived Digital Measurements for Distinguishing Patients From Healthy Controls, Stratified by Fatigue Level

    2 months

  • +18 more secondary outcomes

Other Outcomes (3)

  • Autonomic Function and Symptoms in Participants With Multiple Sclerosis, Post-COVID-19 Condition and Healthy Controls

    Baseline and 8 weeks

  • Agreement Between Blood Pressure Estimated From the Armband Activity Monitor and Cuff-Measured Blood Pressure During Clinical Autonomic Testing

    Baseline visits

  • Time From Notification to Completion of Scheduled Study Application Questionnaires and Performance Tasks Over Two Months

    2 months

Study Arms (3)

Multiple Sclerosis

Participants with a clinically confirmed diagnosis of multiple sclerosis (MS). This group is monitored using two wearable devices and the FIDO smartphone application over two months. At the initial visit this cohort completes demographic questions and the following assessments: the Fatigue Scale for Motor and Cognitive Functions (FSMC), the Hospital Anxiety and Depression Scale (HADS), COMPASS-31, and the Multiple Sclerosis Impact Scale (MSIS-29). The MSIS-29 is administered to this cohort only.

Long COVID

Participants with a clinically confirmed diagnosis of post-COVID-19 condition (Long COVID). This group is monitored using two wearable devices and the FIDO smartphone application over two months. At the initial visit this cohort completes demographic questions and the following assessments: the Fatigue Scale for Motor and Cognitive Functions (FSMC), the Munich Berlin Symptom Questionnaire (MBSQ), the Bell Disability Scale, the Hospital Anxiety and Depression Scale (HADS), and COMPASS-31. The MBSQ and Bell Disability Scale are administered to this cohort only, and characterise symptom severity and functional impairment.

Healthy controls

This group is monitored using two wearable devices and the FIDO smartphone application over two months. At the initial visit this cohort completes demographic questions and the following assessments: the Fatigue Scale for Motor and Cognitive Functions (FSMC), the Hospital Anxiety and Depression Scale (HADS), and COMPASS-31.

Eligibility Criteria

Age18 Years - 65 Years
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64), Older Adult (65+)
Sampling MethodNon-Probability Sample
Study Population

Multiple sclerosis participants will be recruited through Bellevue Medical Group (BMG) and NeuroPraxis Zürich during routine clinical visits. External patients may also participate if they have a diagnosis from a recognized medical institution. Long COVID participants will be recruited from Klinik Lengg during routine clinical visits. External patients may also participate if they have a diagnosis from a recognized medical institution. Healthy controls will be recruited from the general community in Zurich. Recruitment across all groups will use physical and digital study flyers; the Long Covid Switzerland association will additionally support flyer distribution. Interested individuals may contact the UZH study team by email or phone to learn about study aims and eligibility; those willing and eligible will be directed to a study site.

You may qualify if:

  • Confirmed diagnosis of MS (by neurologist) or Long COVID (by medical doctor).
  • Smartphone ownership.
  • Provide written informed consent.
  • Fluent in German or English.
  • Smartphone ownership.
  • Provide written informed consent.
  • Fluent in German or English.

You may not qualify if:

  • Concomitant medication affecting fatigue or ANS such as antidepressants prescribed or adjusted 1 month before the initial visit.
  • Unable to provide informed consent.
  • Unwilling or unable to comply with the study protocol.
  • Pregnancy or lactation.
  • For controls: Diagnosis of any chronic disorders or diseases that may affect fatigue or ANS.
  • For MS: Additional comorbidities that may affect fatigue or ANS such as autoimmune disease and cardiovascular disease.
  • For long COVID: Additional comorbidities diagnosed prior to the first acute COVID-19 infection that may affect fatigue or ANS such as autoimmune disease and cardiovascular disease.

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (6)

Neurozentrum Basel Messeturm

Basel, Basel, 4058, Switzerland

RECRUITING

Bellevue Medical Group - Neurozentrum Sternen / Neurozentrum Bellevue

Zurich, Canton of Zurich, 8001, Switzerland

RECRUITING

University of Zurich

Zurich, Canton of Zurich, 8001, Switzerland

RECRUITING

NeuroPraxis Zürich GmbH

Zurich, Canton of Zurich, 8006, Switzerland

RECRUITING

Bellevue Medical Group - Neurozentrum Seefeld

Zurich, Canton of Zurich, 8008, Switzerland

RECRUITING

Klinik Lengg AG

Zurich, Canton of Zurich, 8008, Switzerland

RECRUITING

Related Publications (2)

  • Gashi S, Oldrati P, Moebus M, Hilty M, Barrios L, Ozdemir F; PHRT Consortium; Kana V, Lutterotti A, Ratsch G, Holz C. Modeling multiple sclerosis using mobile and wearable sensor data. NPJ Digit Med. 2024 Mar 11;7(1):64. doi: 10.1038/s41746-024-01025-8.

    PMID: 38467710BACKGROUND
  • Barrios L, Amon R, Oldrati P, Hilty M, Holz C, Lutterotti A. Cognitive fatigability assessment test (cFAST): Development of a new instrument to assess cognitive fatigability and pilot study on its association to perceived fatigue in multiple sclerosis. Digit Health. 2022 Aug 25;8:20552076221117740. doi: 10.1177/20552076221117740. eCollection 2022 Jan-Dec.

    PMID: 36046638BACKGROUND

MeSH Terms

Conditions

Multiple SclerosisPost-Acute COVID-19 SyndromePatient ComplianceFatigue

Condition Hierarchy (Ancestors)

Demyelinating Autoimmune Diseases, CNSAutoimmune Diseases of the Nervous SystemNervous System DiseasesDemyelinating DiseasesAutoimmune DiseasesImmune System DiseasesCOVID-19Pneumonia, ViralPneumoniaRespiratory Tract InfectionsInfectionsVirus DiseasesCoronavirus InfectionsCoronaviridae InfectionsNidovirales InfectionsRNA Virus InfectionsLung DiseasesRespiratory Tract DiseasesPost-Infectious DisordersChronic DiseaseDisease AttributesPathologic ProcessesPathological Conditions, Signs and SymptomsPatient Acceptance of Health CareTreatment Adherence and ComplianceHealth BehaviorBehaviorSigns and Symptoms

Central Study Contacts

Liliana Barrios, Dr. sc. ETH Zürich

CONTACT

Study Design

Study Type
observational
Observational Model
COHORT
Time Perspective
PROSPECTIVE
Sponsor Type
OTHER
Responsible Party
SPONSOR INVESTIGATOR
PI Title
Principal Investigator

Study Record Dates

First Submitted

August 14, 2026

First Posted

August 24, 2026

Study Start

May 26, 2026

Primary Completion (Estimated)

May 1, 2028

Study Completion (Estimated)

May 1, 2028

Last Updated

August 24, 2026

Record last verified: 2026-08

Locations