Long COVID has no single endpoint and many participants cannot tolerate long clinic visits. Capture runs symptom-burden questionnaires on participants’ phones, records post-exertional malaise at the time of testing, and keeps remote and site data in one study. Free sandbox, no credit card.
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Daily symptom check-in (demo)
Participant 012-0007 · Day 14
Overall symptom burden today
Fatigue today
Did activity in the last 2 days make symptoms worse today?
Hours of upright activity today
What a long COVID trial needs from its EDC
The study data
Long COVID covers a wide range of symptoms that persist or arise after infection. The 2024 National Academies definition describes it as an infection-associated chronic condition lasting at least three months and does not require laboratory confirmation of the original infection. That breadth is why trial design is hard: participants can be dominated by fatigue, cognitive difficulty, breathlessness, autonomic symptoms or post-exertional malaise, and protocols often enroll on a symptom domain rather than on the whole condition. NIH-funded RECOVER trials show the range. A feasibility protocol registered for RECOVER-TLC lists patient-reported measures for fatigue, sleep, cognition, post-exertional malaise (a DePaul Symptom Questionnaire short form), dysautonomia (COMPASS-31) and disability (WHODAS 2.0), and the RECOVER-ENERGIZE trial uses a performance test for one arm and a post-exertional malaise questionnaire for another. Treat these as examples, not a template, and check each registry entry for current endpoints.
For the EDC, the design implication is that patient-reported outcomes are primary data, not a side stream. Each instrument has its own recall period (today, the past week, the past month), its own scoring and its own schedule, and some are sensitive to when they are completed. Build each as its own ePRO task with a schedule and a completion window that matches the recall period, and store item-level answers so any total can be re-derived. The ePRO software page describes tasks and reminders, and the FACIT-Fatigue form structure, EQ-5D structure, sleep diary, fatigue log and cognitive focus diary are starting points. Instrument wording and licences stay with the rights holders and your study documents.
Objective measures need extra thought. Walk tests, exercise tests and orthostatic tests are used in long COVID research, but a patient-led research group and reviews of trial protocols have pointed out that effort can trigger post-exertional malaise, and that its presence at the time of testing can itself change the result. For that reason, add a short pre-test form that records whether the participant has current PEM symptoms and when their last significant exertion was, and a post-test form that records any symptom worsening in the following days. The 6-minute walk test template gives the form structure; whether to include a test at all is a protocol and ethics decision.
Travel and long visits can worsen symptoms and drive dropout. A study can reduce on-site visits to a screening and a small number of follow-ups, run consent remotely with eConsent, and collect most outcomes through phone questionnaires without an app; see BYOD ePRO with no app download and EDC for decentralized clinical trials. Break long questionnaires across several short tasks, widen completion windows so a bad day does not mean a missed entry, and let reminders respect quiet hours.
| Assessment | Screen | Baseline | Wk 4 | Wk 8 | Wk 12 | Wk 24 |
|---|---|---|---|---|---|---|
| Symptom check-in (daily) | D | D | D | D | D | |
| Fatigue and cognition questionnaires | ||||||
| PEM check at visit | ||||||
| Function questionnaire | ||||||
| Adverse events (remote call) |
D = daily check-in
Protocol to build
| Domain | Typical measures in the literature | Where it lives in Capture |
|---|---|---|
| Fatigue | Patient-reported fatigue scales, daily rating | ePRO task; FACIT-Fatigue structure |
| Post-exertional malaise | Questionnaire-based PEM measures, pre- and post-test checks | ePRO task plus site pre-test form |
| Cognition | Patient-reported cognitive function, brief screening tests | ePRO task; MoCA structure if protocol-specified |
| Autonomic symptoms | COMPASS-31 style questionnaires, active stand tests | ePRO task and site form |
| Sleep | Insomnia or sleep diaries | Sleep diary ePRO |
| Function and quality of life | Disability and health-status scales | ePRO task; EQ-5D structure |
| Activity context | Step counts, resting heart rate | Optional native Oura sync |
Instruments are named for structure only. Capture does not supply or verify instrument licences; licence controls exist only on participant questionnaires, where a study team can record a licence number, holder and expiry.
Build the check-in, set wide completion windows and test it on a phone in the free sandbox.
Safety reporting
Long COVID participants are often taking multiple medications and have fluctuating symptoms, so separating adverse events from the underlying condition is the central safety question. Define in the protocol what counts: a symptom that is within the participant’s usual range is baseline, a clear worsening after a study procedure is an event, and a hospitalization is serious. Record onset, severity, seriousness, relationship and action on the adverse event form, with serious events on the SAE report form and a clock for reporting. Intervention-specific events (for example with antivirals, immune therapies or exercise programs) follow the investigational product’s safety plan.
Capture a baseline symptom list at enrollment, as typed rows, so later worsening can be compared with what the participant reported at the start. An edit check can prompt a query when a symptom is reported as new but already appears in the baseline list. For studies with an exercise or rehabilitation component, add a check-in after each session asking about worsening in the following days, so that harm from the intervention is seen as data rather than only as dropout.
Participant-reported data carries a data quality trade-off. Daily entries give a detailed picture but can fatigue participants; weekly entries are lighter but depend on memory. The compliance view shows by study, country and site who is falling behind, so coordinators can call early. Reminders by email or SMS and completion windows keep the schedule tight without a burden on the site.
Build sequence
Upload the protocol and let the AI study builder propose visits and forms. A person reviews before anything is saved.
Infection history, symptom onset and duration, domain scores at screening and structured exclusions.
One task per instrument with a recall-matched window, short sessions and reminders that respect quiet hours.
Pre-test and post-test checks, a baseline symptom list and an adverse event form.
Run a practice participant through consent, a daily check-in and a test visit, then approve forms and go live.
Before first participant
Which definition, minimum duration and how infection is evidenced.
With recall period, schedule and licence terms in the study documents.
Whether tests are used, how PEM status is recorded around them, and safeguards.
Number of visits, length of each questionnaire and window widths.
Baseline versus adverse event, and when an event is serious.
Yes. Each questionnaire opens from a secure link in the phone browser, with no app to install, reminders and a completion window you control.
As structured data: a questionnaire-based measure on a schedule, plus a pre-test form that records current PEM symptoms and recent exertion, and a post-test check on worsening. The protocol and ethics committee decide whether to include exertional tests at all.
No. Capture does not supply or verify licensed instruments or their wording. For participant questionnaires a study team can record licence number, holder and expiry; clinician forms keep their licence in the study documents.
Yes. eConsent, phone questionnaires and remote adverse event calls let a study run with few on-site visits. Which assessments need a visit is a protocol decision.
The study team can enable the native Oura sync per study, and participants connect their own account. No other device is claimed.
Capture is used from Phase 1 through Phase 3 with multi-site support. Platform-trial features such as shared control arms are not claimed here.
Capture provides Part 11-aligned controls: a field-level audit trail, electronic signatures and role-based access. Compliance is shared with the sponsor’s own validated use of the system. This is not legal advice.
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