PAH trials hinge on a walk test, a functional class and a time-to-event, all in a small, expert population spread across few specialist centres. Capture holds the exercise test, the haemodynamics and the clinical-worsening log in one study. Build free in the sandbox, no credit card.
Free sandbox · No credit card · 21 CFR Part 11 aligned
Exercise capacity
Distance walked
SIXMWDChange from baseline
CHG6MWDDerived, read-only
+38 m CalculatedBorg dyspnoea, end of test
BORGResting SpO₂
SPO2WHO functional class
WHOFCWhat a PAH trial needs from its EDC
The study data
Pulmonary arterial hypertension trials have historically been anchored on exercise capacity. The 6-minute walk distance at a fixed week is the classic primary endpoint in short placebo-controlled studies; for example, the STELLAR phase 3 trial of sotatercept used the change in 6-minute walk distance at week 24 as its primary endpoint in adults with WHO functional class II or III disease on stable background therapy, with time to clinical worsening, WHO functional class and NT-proBNP among the secondary measures (ClinicalTrials.gov NCT04576988). Longer event-driven studies shift to a composite of clinical worsening: death, hospitalisation for PAH, or deterioration in exercise capacity or functional class. Your protocol defines the exact components, and the more of them live as structured fields, the less there is to reconstruct before database lock.
The walk test is deceptively fiddly. Distance depends on corridor length, encouragement scripts, supplemental oxygen and time of day, and an unsupervised repeat can look like a treatment effect. In Capture the test is a site eCRF form with typed fields for distance, oxygen flow, Borg dyspnoea, heart rate and tester, plus a calculated change from baseline. The 6-minute walk test template shows a starting layout. A range edit check can flag distances outside a plausible band or a missing Borg score, and each correction is recorded with the old value, new value and reason.
Right heart catheterisation is required for diagnosis and often at baseline, and sometimes again at follow-up. Treat it as its own form: mean pulmonary artery pressure, pulmonary artery wedge pressure, cardiac output and index, and the vascular resistance derived from them in Wood units, with the unit and the cardiac output method recorded. Capture supports calculated fields, and a resistance formula can be built as one; confirm the exact formula and inputs with your cardiologist before you rely on it, since Capture ships specific standard derived fields (such as MAP and BMI) and expects others to be defined by the study team.
A time-to-event endpoint needs an onset date for every event and a clear first-event rule. Build the log with repeating rows, one per event, with type (death, PAH hospitalisation, decline in walk distance, functional class worsening, escalation of therapy), date, and the supporting visit. Repeating rows each carry their own audit trail. The adverse event template separates safety events from efficacy events so the same hospitalisation is not counted twice by accident. If a committee adjudicates events, give it a clean export; the committee process is outside Capture.
Week 24 walk tests entered
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Worsening events logged
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walk tests complete
walk tests complete
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Protocol to build
| Protocol element | What the data looks like | Where it lives in Capture |
|---|---|---|
| Diagnosis and eligibility | Haemodynamic criteria, group classification, functional class, background therapy | Eligibility screening template with range checks |
| Exercise capacity | Distance, oxygen, Borg score, tester | 6-minute walk template with change from baseline |
| Functional class | WHO class I to IV at each visit, rater | Single-choice site form field |
| Haemodynamics | mPAP, PAWP, cardiac output, derived resistance | Dedicated form with a study-defined calculated field |
| Biomarkers and safety labs | NT-proBNP, liver tests, haemoglobin | Laboratory template |
| Vitals | BP, heart rate, SpO₂, weight | Vital signs template |
| Clinical worsening | Type, date, hospital stay, source | Repeating event log |
| Quality of life | Disease-specific or generic measures | EQ-5D layout; licences stay with your study documents |
Capture does not connect to echo, catheter lab or walk-test devices. Results are entered by site staff.
Build the walk test, the functional class and the worsening log, and let your site investigators try them. Free sandbox, no credit card.
A rare disease, few centres
PAH is a rare disease treated at a limited number of expert centres, so enrolment is slow and each site matters. QR-code enrolment, site-level participant numbering and a separate site coordinator portal keep a small network organised. PII segregation means coordinators see participant names while researchers work with coded IDs. See multi-site clinical trial management for the cross-site view.
Most PAH programmes continue into an open-label extension for the same participants, often for years, and participants on placebo usually cross over. Build the extension as an epoch of the same study rather than a new database so the baseline, walk-test history and audit trail stay continuous. The long-term extension study page covers the design.
Because many sponsors are small rare-disease companies, see also the page on rare disease clinical trial software for the foundation-led side. If a registry runs alongside the trial, registry studies explains how the data models differ.
Build sequence
Upload the protocol (PDF, DOCX or DOC) and let the AI study builder propose the schedule and forms for review. Nothing is saved until a person approves it.
Write the clinical-worsening definition into the form options exactly as the protocol states it.
Allowed windows around week 12 and week 24, plausible distance bands, SpO₂ and NT-proBNP ranges.
Add the catheterisation fields and any derived resistance calculation, and have the cardiologist check the result against a worked example.
Run practice participants through screening, week 24 and an extension visit, then read the audit trail of a corrected walk distance.
Approved forms lock for live use. Real participants start the paid live phase.
Before first participant
Corridor length, encouragement script, oxygen rule and tester recorded on the form.
Components and the first-event rule identical in protocol, form and analysis plan.
Derived values checked against a worked example before go-live.
Windows match the protocol so late tests are visible.
Epochs and consent for rollover agreed before the double-blind phase closes.
CSV or Excel with the data dictionary opened in the statistics package.
Yes. The walk test is a site eCRF form with distance, Borg score, oxygen and tester fields, and a change from baseline can be shown as a calculated field. A range edit check can flag implausible distances.
As a repeating event log with type, date and source. Each row has its own audit trail, so the first-event date for a time-to-event analysis is traceable.
Capture supports calculated fields, and a study team can define one. It does not ship a PAH-specific resistance formula, so confirm the formula and inputs with your cardiologist and test it with a worked example.
No integration is claimed. Site staff enter results from the report, and source data verification can be set per field.
Yes. Build the extension as an epoch so baseline data, the walk-test history and the audit trail continue without a second database.
Yes. Capture is suitable for Phase 1, 2 and 3 studies, and multi-site work uses site-level numbering, a site coordinator portal and by-site exports.
The sandbox is free with every feature, no credit card and no time limit. You pay only once you go live with real participants. Pricing is not published on the site, so ask for terms for your study.
Keep exploring
6-minute walk test template
Distance, Borg score and oxygen.
EDC for COPD and asthma trials
The airway side of respiratory research.
Long-term extension study software
Open-label rollover as an epoch.
Vital signs template
BP, heart rate and SpO₂.
Multi-site trial management
Few centres, one view.
Pricing
Free sandbox, pay at go-live.
Free sandbox with every feature. No credit card, and you pay only when you go live.