A generalized myasthenia gravis trial pairs a patient-reported daily-living scale with a clinician-performed strength exam, tracks antibody status and rescue therapy, and runs long extensions. Build it in Capture, test it free, and pay only when you go live.
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| Assessment | Screen | Day 1 | Wk 1 | Wk 4 | Wk 12 | Wk 26 |
|---|---|---|---|---|---|---|
| Patient-reported daily-living scale | ||||||
| Clinician strength exam (13-item style) | ||||||
| MGFA class and antibody status | ||||||
| Disease-specific quality of life | ||||||
| Rescue therapy / IVIG / PLEX log | ||||||
| Adverse events and infections |
x = form completed at the visit
What a myasthenia gravis trial needs from its EDC
The study data
Look at the endpoint sections of registered generalized myasthenia gravis trials and a pattern appears. Several phase 3 registrations make the change in the MG-ADL total the primary endpoint at week 12 or 26. Others use the Quantitative Myasthenia Gravis score, for example the change from baseline to week 24 in a registered immunoglobulin study. The MG-ADL is a short patient-reported scale of eight items, each scored 0 to 3, total 0 to 24. The QMG is a clinician-performed examination of thirteen items, each 0 to 3, total 0 to 39. The quality-of-life companion, the MG-QoL15r, has fifteen items and is usually a secondary. These ranges come from the instrument literature, so confirm them against your licensed version.
The data problems are different for each scale. The patient scale reflects the previous week, so a visit that happens during an infection or a rescue infusion changes the answer without anything being wrong with the form. The QMG is a performance test, with timed arm and leg holds, a forced vital capacity and a grip strength reading, so the numbers depend on the rater and the time since the last cholinesterase inhibitor dose. Capture records every entry under the user who made it, with old value, new value and reason for any change, and calculated fields show totals read-only so the sum is never typed twice.
Use screening to capture what the protocol uses as entry gates: disease duration, MGFA class (I to V in the classification), thymectomy history, and antibody status. These are straightforward fields on a screening form, but they should be locked once the form is approved and used for stratification. If your design stratifies randomisation by antibody status or baseline score, see clinical trial platform with randomization; the pricing page describes stratified, blinded allocation.
Scores
Rater
RATERTime since last cholinesterase inhibitor dose
TSINCECalculated from two date-times
3.5 h CalculatedTotal strength score
QMGTOTSum of item scores, read-only
17 CalculatedChange from baseline
CHGMeets the protocol responder threshold
IVIG or plasma exchange in the last 4 weeks
RESCUEYes: confirm date on the rescue log
Protocol to build
| Protocol element | What the data looks like | Where it lives in Capture |
|---|---|---|
| Daily-living scale | Eight item scores, total, weekly recall | Participant questionnaire on their phone, or a site form if administered in clinic |
| Strength examination | Timed holds, vital capacity, grip; item and total score | Site eCRF form with calculated total and rater field |
| Quality of life | Fifteen-item disease-specific measure | Participant questionnaire at scheduled visits; see PROM guide |
| Antibodies and MGFA class | Positive/negative by antibody, class I to V | Screening form fields, locked once approved |
| Rescue and background therapy | IVIG, plasma exchange, steroid and pyridostigmine changes with dates | Repeating-row concomitant medications form, each row with its own audit trail |
| Infusion or injection visits | Dose time, vitals, reactions | Visit form plus vital signs template |
| Adverse events | Infections, seriousness, relationship | Adverse event form and SAE workflow |
| Open-label extension | Same participants, new epoch | Epochs and arms in one study; see long-term extension software |
Instrument wording is yours to supply. Licences stay with your study documents; Capture does not supply or verify instrument licences, and licence controls exist only on participant questionnaires.
Upload the protocol, let the AI draft visits and forms, and test responder logic with sample data. Free sandbox, no credit card.
Operations
Rater consistency matters more in a strength examination than in most scales, and sponsors often limit the number of qualified raters per site. In Capture each site form carries the signing user, and role-based access keeps a rater from changing the work of another. Add a rater field to the form so the analysis can adjust for it. If your protocol demands that the same rater scores a participant across visits, an edit check can raise a query when the rater changes.
Myasthenic crisis, hospitalisation and exacerbations are safety events and efficacy events at once. Record them on the adverse event form with seriousness assessed, and keep a separate dated log of rescue therapy so the statistician can apply the protocol rule for visits after rescue. Whatever your rule is, the point for the EDC is that the dates are entered, time-ordered and auditable. Reference AE seriousness decision tree for how seriousness is classified.
Programmes in generalized MG usually run a double-blind period followed by open-label extension. Build the blind period and the extension as epochs with their own visit plans. Blinded roles never receive treatment-arm values, enforced by masked database views. If your trial includes weekly infusions or self-injections at home, the participant questionnaire can carry a short home-dosing record next to the weekly scale, and reminders go by email or SMS. For the wider neurology picture see EDC for CNS and neurology trials; this page stays with the myasthenia endpoint model.
Before first participant
Rights-holder terms for MG-ADL, QMG and MG-QoL15r filed in study documents.
Thresholds, baseline definition and post-rescue handling agreed with the statistician.
Named raters per site, with a rater field on the strength form.
Screening form approved before the first participant.
Dated rows, edit check against scored visits.
Open-label visit plan ready in the same study.
Yes, as typed item fields with a read-only calculated total on a site form, or as a participant questionnaire for the patient-reported scale. Supply your own licensed wording; Capture does not provide it or verify the licence.
Yes. It can be a participant questionnaire opened from a secure link in the phone browser, with reminders and a completion window you set. No app install is needed.
Log each IVIG or plasma exchange course as a dated row on a repeating-row form. An edit check can raise an automatic query when rescue is recorded near a scored visit; the exclusion rule itself belongs in your analysis plan.
Yes. Epochs and arms let a double-blind period and an extension live in one study with the same participant record.
The pricing page describes stratified, blinded allocation that runs automatically. Check the pricing page for which plan includes it.
The sandbox is free with every feature and no time limit. You pay once you go live with real participants; plan rates are on the pricing page.
Free sandbox with every feature. No credit card, and you pay only when you go live.