Differentiating between eSource and EDC: Everything You Must Know

Mansha Kapoor
April 9, 2023

The 2020 pandemic has been a game-changer for the healthcare industry. Patient’s perspective and commercialization have given a fillip to increased digitization across its value chain. There is a sense of urgency to incorporate upgrades and innovations, keeping patient-centric design in purview. The healthcare industry is therefore witnessing investments like never before, the area of interest being remote clinical capabilities.  EDC (Electronic Data Capture) is just such a capability to capture and collect data electronically. It stores the patient data that is accrued during clinical trials. With eSource, researchers can access the progress of a trial and treatment in detail.

What is EDC?

Digitization of processes has almost eliminated the hiccups that the clinical trial industry has been facing. A successful trial/treatment largely depends on a practical Data capture roadmap. Data capture is the process by which information is harvested from any document. It could be a structured or an unstructured one, paper or electronic, and then is changed into a machine-readable digital format. A hospital pharmacy is a classic example of data capture being employed to ensure the smooth working of inventory management. Earlier data capture involved human intervention and often resulted in high costs: the method was time-consuming and error-prone. There has been a shift from manual data entry toward automated data capture.  It is the initial phase of digitization and, if carried out properly, will help researchers and clinicians store, organize, search, and retrieve documents without any time leaks.

EDC is a web-based software application used to collect, clean, transfer, and process data in clinical trials. The data can vary from Medical data about patients’ status and conditions to safety data regarding clinical trials or test results from laboratories and suppliers, Patient’s information about their quality of life, and even their vital parameters about blood sugar or blood pressure. It can even access demographic information and the medical histories of participants.  But all the clinical trial data collected from patients and subjects are computerized. Technology transfers the same self-data to the research laboratory with minimum errors and improved data quality. Time taken and costs incurred are thus effectively slashed. 

There are various entry procedures for EDC. Clinical trial data is recorded on paper and then transferred to the electronic case report form or eCRF. Another is the Interactive Voice Response (IVR). In this, the patient reports his responses directly telephonically or through the point of contact data collection system. It is the electronic patient-reported outcomes or ePRO;   tablets and digital pens are used to collect data. EDC solutions are widely used by research organizations, biotechnology, and pharmaceutical industries. It is also used to carry out safety surveillance activities.

Components of EDC

An organization can use either commercial, open source or in-house developed EDC systems. It could be a standalone, server-based, or multi-site, Web-based system. Whatever the source, there are certain commonalities that all EDC systems have, regardless of their architecture. The design includes streamlining data collection, managing data collected, and data exchange between various devices and systems. A typical EDC system would have a graphic user interface for data entry, a data validation component, and a reporting tool. And the standard features of an EDC system include the following:

  1. Standard electronic case report forms (eCRF)
  2. Data entry with real-time data validation
  3. Query management
  4. Data audit trail
  5. Inspection of data changes
  6. Data exporting
  7. Multi-level user access
  8. Report generation. 

Therefore, the Electronic Data Capturing tool is versatile and powerful. It can extract data from multiple sources, including paper forms, web forms, and mobile devices, thus building a database and analyzing it simultaneously. Organizations achieve efficiency by avoiding worries about data integrity problems caused by human error and connectivity issues. The volume of information collected before, after, and during the trial is mammoth. Managing, storing, and retrieving it is of massive priority to every organization carrying out a trial. The adoption of EDC is therefore becoming more and more indispensable.

Advantages of EDC

Electronic Data Capture systems assure data quality and consistency, which facilitates their implementation in all trial locations without compromising the integrity of the trial.

The digital character of the data capture mode allows the information to be accessed without digging through reams of paper and pen information. Internet availability is the only criterion, and an organization can carry out a trial internationally across different time zones without worrying about working hours. 

Maintaining a record of electronic forms is more accessible than filing paper questionnaires. 

Patient compliance to study requirements could be quicker as they can access real-time information about the study status of the trial.

Quicker integration of data from across all sources results in faster information processing for the researchers, which helps them make better-informed decisions towards expediting clinical development.

EDC ensures data security. Information in the system is backed at least once daily and could be more during the collection phase. Somebody can easily update it with minimal activity, and all the relevant information can be updated with a few clicks in the central database, allowing changes to be made instantly. Thus, ensuring error-free entry. 

It enhances Patient Safety. EDC cuts down on time invested in reporting responses in a trial, and it can detect and report an adverse effect of an administration. e-CRFs have been adopted by the FDA as a part of their Good Clinical Practice guidance on improving data quality in clinical studies.

EDC covers and keeps track of all aspects of a clinical trial, including enrolment, participation, vital signs, and treatments.

What is e-Source?

e-Source is all about Clinical Data Management. The FDA defines source data as “all information in original records and certified copies of original records of clinical findings, observations or other activities in a clinical investigation used for reconstructing and evaluating the investigation.” It issues guidelines for the Industry on the significantly optimized use of eSource. “Many data elements (e.g., blood pressure, weight, temperature, pill count, resolution of a symptom or sign) in a clinical investigation can be obtained at a study visit and entered directly into the eCRF by an authorized data originator. This direct data entry can eliminate errors by not using a paper transcription step before entry into the eCRF. For these data elements, the eCRF is the source”. Based on these official guidelines, eSource can be defined as the electronic data collected at the beginning of the exercise. eSource is, therefore, not a mobile app but a way of collecting data wherein the data is entered directly into electronic records. Talking about e-Source could be about a fillable PDF or wearable health devices and even Electronic health records or EHR. It is not about an application or program but would mean electronic source data from various software systems.

Back in time, any investigation for evaluating purposes would have meant mountains of paperwork and engagement of human resources in researching information, scanning, and printing hard copies. Today a whole array of systems can generate and capture data. These devices include Digital medical devices (like imaging or laboratory machines, electronic diaries, sensors, or wearable devices. Any data initially recorded in a digital/electronic format would come under eSource.

What are the Benefits of Implementing eSource?

eSource can improve the quality and efficiency of clinical trials, ultimately leading to faster and more reliable results, improved patient safety, and better drug development outcomes. Following are the main advantages of implementing eSource:

1. Streamlines and speeds up investigations

With eSource /digitized source data, the collection process has become simple and easy to navigate by both the operator and the patient recording outcomes. It has eliminated the use of paper forms and manual, by-hand recordings. There is no need for transcriptions, thus ensuring minimal errors and cleaner and more reliable data. The latter is an absolute necessity for clinical trials. This, in particular, applies to overseas trials that are highly expensive and complex. eSource helps streamline costs, timelines, patient recruitment, and recording responses. It also works towards harmonizing trial initiatives in case of multi-regional or trans-global exercises. Together, it translates into speedier trials and outcomes that help market medical solutions/ treatments. 

2. Facilitating quick communication

eSource allows traceable real-time data to be captured and retrieved from global trials. Even at geographical sites with limited internet availability, eSource enables the site staff to gather data offline and sync it automatically to EDC when the connection is more robust. The rest of the team on the other side of the globe instantly accesses and assesses the information, and there is almost no time lag. A lot of time is also saved in getting approvals digitally. A worker does not have to get physical signatures and paperwork done. The admin procedures can be done online using devices and tools.

3. Enhancing patient recruitment and retention

Patient recruitment and retention are two significant challenges to a successful clinical trial. A region might boast a good patient pool and cultural receptivity to trial participation but sustained and proactive participation could become a problem during the trial. The trial must be patient-centric, with fewer or almost no site visits. Comprehension of what the patient has to do also goes a long way in enrolling and engaging the participants. To ensure this, eConsent and ePRO provide certain flexibility and freedom to the patient. In turn, it gives the researchers more bandwidth in terms of time and quality of results and, therefore, a faster reach to regulatory approvals.

4. Remote monitoring

By using eSource, sponsors and CROs can work across sites around the globe. Carrying out international trials gives them access to diverse populations and a flexible recruitment schedule. For example, Pfizer tested its covid vaccine across six countries and five continents. A sponsor can retrieve and review data remotely without the researcher having to fax copies of data. eSource refers to the electronic data capture at the point of care, eliminating the need for paper-based records. With the rise of remote monitoring due to the COVID-19 pandemic, eSource has become an essential tool for ensuring the continuity of clinical trials without jeopardizing participants’ safety and privacy. 

eSource facilitates remote monitoring by providing real-time access to study data. Sponsors and CROs can carry out document verification of medical records and imaging studies and  monitor study progress in real-time. So eSource enablement reduces the need for on-site monitoring visits, thus ensuring compliance with social distancing guidelines.

Can both EDC and eSource be used?

It is indeed possible to use EDC and eSource. Both may be designed and aimed at recording data digitally at the source of the trial. But a slight difference makes it possible for an organization to have both operable within a trial. EDC are templates that Clinical Research Associates fill. This is done after the patient has left the trial site or, even later, from a patient’s EHR (Electronic Health Record). This late entry creates room for possible errors.

On the other hand, eSource is a technology specifically for clinical trial operators for participating physicians who must record data at the moment of the examination. There is no delay or lacuna in recording information, and the outcome/compliance-related information is keyed in while the patient is present, at the source, from the source. It will also have every tiny detail that information researchers might need, starting from the standard of care, participants' initials, their date of birth, the date and time of the sample collected, and all the other data needed from the perspective of operational workflow.

Participant data is continuously collected throughout the trial and stored in EDC software: the date and time of collection and the test results. The data for a particular trial is in one place, making it convenient for sponsors to quickly retrieve, analyze, and report. An investigator-initiated trial may have EDC and eSource to collect, manage, and retrieve data. 

Can a Clinical Trial only have e-Source? 

Biopharma and MedTech companies are opting more for e-Source to improve their clinical trial results. Its patient-centric character and simplification of the trial processes make it a preferred tool for capturing and recording data. e-Source also assures quality data and broad reach. Regulating bodies advise the use of e-Source for optimized results.  


EDC has undoubtedly been the standard data collection method for several years before esource emerged as a more advanced and flexible means of capturing data at source. 

There are significant differences between EDC and eSource; their fitment into a trial largely depends upon the study design and needs of the research team. EDC is most apt for studies with structured data entry requirements, and eSource is ideal for studies with complex data requirements, including those that assimilate patient-reported outcomes or imaging data. 

eSource technology could be relatively new compared to EDC, but it has shown its efficacy and agility in enhancing data quality, reducing data entry errors, and streamlining clinical trials. With its increasing and ready adoption, eSource technology is expected to gain speedier traction and become the preferred method for data capture. 

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