- An EDC is the software that hosts the eCRF, checks entries as sites type them and keeps an audit trail.
- The EMA guideline on computerised systems (2023) expects audit trails that ordinary users cannot switch off.
- Across 27 AP-HP studies, eCRFs cost €374 per patient against €1,135 for paper (BMC Med Res Methodol, 2014).
- Choose an EDC on mid-study changes, edit checks, audit trail access and export formats, not on feature counts.
Electronic data capture (EDC) is the system that turns a protocol's case report forms into web forms, checks each value as the site enters it, and keeps a record of every change until the database is locked. If you run data management on a trial, the EDC is where your data lives, and where inspectors will look first. A retrospective comparison of 27 studies sponsored by the Paris public hospitals (AP-HP), published in BMC Medical Research Methodology in 2014, put the cost at €374 per patient with electronic CRFs against €1,135 with paper.
What is electronic data capture (EDC) in clinical trials?
Electronic data capture (EDC) is software that collects clinical trial data through electronic case report forms (eCRFs) instead of paper. The EDC hosts the forms, runs automated checks on each entry, manages queries between sites and data managers, records every change in an audit trail, and exports the locked data for analysis.
Two terms get mixed up. The eCRF is the form: the set of pages and fields the protocol requires for each visit. The EDC is the system that hosts those forms, controls who can enter or change data, and stores the history. Our article on what an eCRF is and how it is built covers the form itself.
The EMA guideline on computerised systems and electronic data in clinical trials, adopted in March 2023, lists eCRFs among the systems in its scope and notes that they may hold data entered directly at the site, transcribed from another source, or transferred from other systems. That mix matters: your EDC must record where each value came from.
An EDC is one component of a wider set of tools. The CTMS tracks sites, visits and milestones; the EDC holds the clinical data. The difference is detailed in CTMS vs EDC, and the article on clinical trial platforms explains how EDC, ePRO, eConsent and randomization fit together.
How does an EDC system work in a clinical trial?
An EDC follows the life of the study database: the data manager builds the eCRF from the protocol and programs the edit checks, the team tests and releases the study, sites enter data, the system raises queries on inconsistent values, monitors review, investigators sign, and the data manager locks the database before export. Each step leaves a trace in the audit trail.
The table below shows who acts at each stage and what the system records.
| Stage | Who acts | What the EDC does |
|---|---|---|
| Build | Data manager | Turns the protocol's visit schedule into forms, fields and edit checks |
| Test and release | Data manager, sponsor QA | Runs the study in a test environment, then releases the validated version |
| Data entry | Site staff, investigator | Records each value with the user, date and time |
| Edit checks and queries | System, data manager, site | Flags out-of-range or inconsistent values and tracks each query until it closes |
| Monitoring | Clinical research associate | Supports source data verification and review, on site or remote |
| Sign-off | Investigator | Captures the investigator's electronic signature on the data |
| Lock and export | Data manager | Freezes the database and exports the data for statistical analysis |
Two examples show where the stages bite. A site enters a systolic blood pressure of 1,400 mmHg: a range check fires at entry, and the site corrects the typo before the monitor ever sees it. A protocol amendment adds a laboratory test at visit 4 halfway through the study: the data manager adds the field to the live study, and the audit trail shows which version of the form each participant's data was entered in.
What do EMA and FDA expect from an EDC?
EMA and FDA expect an EDC to keep data attributable, traceable and secure for the life of the trial. In the EU, the EMA guideline of March 2023 sets the bar for audit trails, edit checks and investigator sign-off. In the US, 21 CFR Part 11 governs electronic records and signatures, and the FDA's final Q&A guidance of October 2024 explains how it applies to clinical investigations.
Three expectations in the EMA guideline shape how you configure and run an EDC:
- Audit trail. The guideline asks for an audit trail on the creation and every modification of electronic data, secure, computer generated and timestamped, which ordinary users cannot deactivate.
- Edit checks. Edit checks should match the protocol, be validated, and be documented. If you pause one during the trial, you document and justify the pause.
- Control of the data. The sponsor should not change data entered by the investigator or the participant unless the investigator authorizes it, and the investigator signs off the data at milestones defined for the trial.
The guideline also expects risk-based audit trail review: the team reviews critical data on an ongoing basis to spot missing values, entries made at unexpected hours or signs of manipulation. ICH E6(R3), adopted by ICH on January 6, 2025, frames all of this as quality proportionate to risk. Our article on EDC regulatory compliance goes through 21 CFR Part 11 point by point.
Is an EDC better than paper case report forms?
Published comparisons favor electronic capture on cost, entry time and errors, with small samples. Across 27 AP-HP studies, eCRFs cost €374 per patient against €1,135 for paper (2014). In a randomized trial at the Charité in Berlin, published in 2017, electronic entry took 8.3 minutes against 10.5 on paper, with 0 entry errors against 3.
Both studies carry limits you should know before you quote them. The AP-HP study, by Le Jeannic and colleagues, was retrospective and not randomized; its authors attribute part of the cost gap to the larger number of patients in the eCRF studies, and the shorter time to database lock (31.7 against 39.8 months) was not statistically significant. The Charité trial, by Fleischmann and colleagues, randomized 27 patients inside one weight-loss study.
The stronger argument for EDC is control. Paper offers no range check at the moment of entry, no automatic query tracking and no audit trail that shows who changed a value and why. The comparison of EDC and paper details the operational side, and why sponsors move to an EDC covers the data quality case.
Which criteria matter when you choose an EDC?
Choose an EDC on how it handles the events that disrupt a study: protocol amendments, query volumes, monitoring visits and the final export. Feature lists look alike from one vendor to the next; the differences appear when you change a live study, review an audit trail or hand data to a statistician.
The table below lists the checks to run during a demonstration or a trial account.
| Criterion | What to check | Why it matters |
|---|---|---|
| Mid-study changes | Can you add a field to a live study without downtime or data migration? | Amendments arrive after sites have entered data |
| Edit checks | Do range and cross-form checks fire while the site types? | Fewer queries reach the data manager |
| Audit trail access | Can monitors and inspectors read the trail without IT support? | The EMA guideline expects direct access |
| Exports | Which formats: CSV, SAS, CDISC ODM? | Your statistician's tools decide |
| Study build | Who builds the study: your team or the vendor's? | Each change then waits in the vendor's queue |
| Validation documents | Will the vendor share its validation file? | Your QA team needs it before go-live |
Our five-step method to choose an EDC turns these checks into a selection process, the list of EDC features to verify goes into detail, and the comparison of 13 EDC platforms sorts vendors by study type. Academic sponsors will find budget and export questions in choosing an EDC for academic trials.
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How Datacapt approaches electronic data capture
Datacapt is a clinical trial platform whose EDC lets your team build and change studies without filing a change request with the vendor. Edit checks on ranges, cross-form rules and mandatory fields fire while site staff type. Datacapt stamps every entry, change and signature with a user, a date and a reason, so the audit trail answers an inspector's question without an export.
The eCRF is built on the CDISC ODM format, and data exports to CSV, XLSX, PDF and SAS. Mid-study changes go live without redeployment or data loss, and the validation documentation is available on request. The same database serves ePRO, eConsent, randomization and medical coding, which removes the reconciliation step between separate tools.
The differences between EDC systems show during amendments, inspections and database lock. Before you sign with a vendor, ask to make one protocol amendment in a test study and to read the audit trail it leaves.
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Sources
- European Medicines Agency, GCP Inspectors Working Group, Guideline on computerised systems and electronic data in clinical trials (EMA/INS/GCP/112288/2023), 2023.
- U.S. Food and Drug Administration, Electronic Systems, Electronic Records, and Electronic Signatures in Clinical Investigations: Questions and Answers, 2024.
- Le Jeannic A, Quelen C, Alberti C, Durand-Zaleski I, Comparison of two data collection processes in clinical studies: electronic and paper case report forms, BMC Medical Research Methodology 14:7, 2014.
- Fleischmann R, Decker AM, Kraft A, Mai K, Schmidt S, Mobile electronic versus paper case report forms in clinical trials: a randomized controlled trial, BMC Medical Research Methodology 17:153, 2017.
What does EDC stand for in clinical trials?
EDC stands for electronic data capture. In clinical trials, an EDC is the software that collects participant data through electronic case report forms (eCRFs), checks each entry against rules derived from the protocol, tracks queries with the sites, records every change in an audit trail and exports the locked database for statistical analysis.
What is the difference between an EDC and an eCRF?
The eCRF is the electronic form that holds the data the protocol requires at each visit. The EDC is the system that hosts the eCRF, controls user access, runs edit checks, manages queries and keeps the audit trail. A study has one eCRF design; the EDC runs it from first entry to database lock.
Is an EDC system required by regulators?
No regulation requires sponsors to collect data electronically. The EMA guideline on computerised systems (2023) states there is no requirement or expectation to use computerised systems for data collection. When you do use an EDC, it must meet the guideline's expectations on validation, audit trails, access control and investigator sign-off, and, for data submitted to the FDA, 21 CFR Part 11.
Who enters data in an EDC?
Site staff and investigators enter most of the data in the EDC, from source documents or directly at the visit. Data managers build the forms and raise queries, clinical research associates review and verify the data, and the investigator signs it off. Under the EMA guideline, the sponsor does not change data entered by the investigator without the investigator's authorization.
Florentin combines clinical research know-how with a true passion for product design. Attentive to detail and obsessed with user experience, he ensures that Datacapt remains a high-performance platform that’s also intuitive and accessible to every user.
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