eSource DDC

DDC vs. EDC: Frequently Asked Questions

Direct data capture (DDC) and electronic data capture (EDC). They sound the same. But when you dig a little deeper, there are fundamental, crucial distinctions that make a significant difference in clinical research workflows, data quality, and timelines. Here, we briefly cover the differences (for greater detail, read eSource: 6 Steps to Understanding) and answer some of the biggest questions we get about DDC from clients.

DDC vs EDC: What’s the Difference?

Understanding the difference requires clarity on the definition of eSource. But first of all, what do we mean by source? 

Source documentation is the fountainhead of data — that initial data recording, whether it’s a digital thermometer reading, a BP entry in the electronic medical record (EMR), a paper form, or an ePRO entry. eSource is simply the direct digitization of source data with no intermediate steps. Collecting data in this format is better for timelines, audit tracking, accuracy, consistency, and overall data quality and visibility.

At Clinical Ink, eSource is a complete, integrated ecosystem — the Lumenis™ platform, which includes digital clinical outcome assessments (eCOA), patient-reported outcomes (ePRO), and eConsent forms. It also encompasses direct data capture (DDC) for other types of information collected during a clinical trial, such as vital signs, ECG, and blood or urine screens.

But here’s the key: These data points are entered into the DDC tool in real time, as they are collected. This is critically different from standard EDC workflows, in which data points are collected in a variety of ways during the patient visit and later transcribed into the EDC tool. DDC is direct data entry at the moment that matters, when the patient is still present (and errors can still be corrected). This source data is cleaner, which translates to fewer queries and increased productivity for sites. Eliminating the transcription step not only saves time and reduces error, but it also eliminates the need for source data verification (SDV) — one of the biggest burdens of study monitoring.

What If There Are Existing Medical Records That Need to Be Incorporated?

In any trial, at a patient’s first visit, historical information such as medical history, laboratory, or medication data will likely need to be transferred into the research record. It’s no different when you implement a DDC system. Pre-existing information in the paper or electronic medical record, the PRO record, or elsewhere may need to be transcribed into the DDC tool – the same way it would need to be transcribed into an EDC system. Because these initial data points were, in fact, transcribed (unlike most DDC), they will need to be verified. So once de-identified, they can be scanned and uploaded to the Lumenis platform to allow for remote SDV. In contrast, new data collected will be entered directly into the DDC electronic research record and will not need to be verified.

What Are the Regulatory Concerns with eSource?

Over the years, regulatory authorities have discussed data capture frequently with industry. With the advent of tools, technologies, and approaches that embrace a more direct capture of data, the FDA, the EMA, and other regulatory agencies have issued eSource-related white papers and guidances, embracing this type of approach. In 2019, the EMA came out with a qualification opinion on eSource in which the Clinical Ink Lumenis platform is identified more than ten times in relation to its use in multiple eSource studies conducted in Europe. Throughout, the agency makes it clear that eSource is a very viable and, in fact, preferred method for data collection.

Of course, you want to make sure your vendor can configure their systems to be compliant with applicable regulations — 21 CFR Part 11, GDPR, HIPAA, and any other relevant guidance set forth by local regulatory agencies.

These references should provide perspective:

July 2019 – EMA
Qualification opinion on eSource Direct Data Capture (DDC)

September 2013 – FDA
Guidance: Electronic Source Data in Clinical Investigations

August 2010 – EMA
Reflection paper on expectations for electronic source data and data transcribed to electronic data collection tools in clinical trials

What About Integration With an EDC System? How Do I Query, Review, and Clean My Data?

When you use DDC, there is no need for electronic data capture. Our Lumenis eSource ecosystem more than takes its place with configurable, clinical modules: Direct Data CaptureeCOAePRO, and eConsent. DDC can capture sources EDC cannot. You get not only the needed case report form analysis data, but you also get audio, video, photos, handwritten notes, and anything you can scan or image. A single application consolidates everything from all four modules into one data set, cleaned during the moment that matters (the patient visit), and uploaded to the portal in real time, ready to be reviewed remotely. No paper, no transcription, no source document verification (SDV).

If necessary, as in the case of pre-existing medical records or results from central labs, sites can use the capture tablet to scan and upload original source materials to our web portal for remote SDV — remote comparison with transcribed entries. In the case of labs, the source data capture tool can be programmed with the appropriate local lab reference ranges to simplify central review.

What If I’m Not Sure About Internet Connectivity? What Options Should I Consider When Looking for Solutions That Give Me the Ability to Carry Out Decentralized, Home-Based or Hybrid Studies?

Electronic, tablet-based DDC systems are ideally suited for highly mobile data collection. Devices in homes, ambulatory centers, or remote medical locations can function independently and facilitate proper study execution through well-designed workflows and edit checks that ensure the right data is collected during the patient visit. Then, as soon as the Internet can be accessed, the data can be uploaded to the web portal for review by the broader study team.


Learn more about how eSource saves you time, produces cleaner data, and builds confidence in both decision-making and study conduct.

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Topics: eSource DDC

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