An Introduction to EDC Systems in Clinical Trials

If you need an EDC system for data collection, please contact us at

Data, data, data. Since clinical research is conducted by studying large numbers of patients, clinical trials are all about data, from its collection to its analysis. Not long ago, all this information had to be gathered and stored by paper-based methods. Today, Electronic Data Capture (EDC) systems offer an easier method for managing data in clinical trials.

What is Electronic Data Capture?

Electronic data capture (EDC) consists of gathering and storing clinical data in digital format. Electronic data capture is implemented by using a web-based system for digital data management.

Typically, EDC systems provide:

  • a user interface component for data entry
  • a validation component to verify data
  • a reporting tool to monitor the progress of the collected data
  • an export tool for moving data to another location for further analysis.

EDC systems can also include additional functionalities for cleaning, searching, and analyzing data, as well as communicating among users. 

These systems are used in the life sciences, clinical trials and in the biotechnology field.

What are EDC systems in the context of clinical trials?

Within the context of a clinical trial, an EDC system is understood as an electronic case report form (eCRF), namely, a web-based tool to collect clinical data. 

Before EDC systems had been developed, clinical trials used paper-based case report forms. These paper forms were completed by staff at individual clinical sites and then sent to a central location where they were transcribed into an electronic database. All the data then had to be reviewed for any kind of error, from those made by the person completing the form to transcription errors, before analysis could begin. 

This paper system is obviously labor-intensive, time-consuming, and liable to error. With an eCRF, clinical staff at individual sites can submit case report forms directly into a central digital database.

What are the advantages of an EDC system?

The advantages of electronic data collection have become increasingly apparent, but let’s mention some of the benefits of using EDC systems in clinical trials.

Using an eCRF streamlines data collection. EDC systems are internet-based software programs, so clinical sites can access the system from any computer and enter clinical trial data directly into a central database, eliminating the need for shipping and transcription. 

Additionally, using an eCRF facilitates the data cleaning process. In an EDC system, data reviewers can access and review the data immediately. Since EDC systems include traceability features, data reviewers know exactly who to query when questions or discrepancies arise. Data can be locked until all queries are resolved.

Most importantly, EDC systems help ensure the success of a trial. The regulatory requirements of clinical trials have become increasingly complex and demanding. This had an impact on clinical trial failure rates, as high as 80 percent. Some of these failures are due to poor data management or the inability to meet regulatory requirements regarding data. Implementing an EDC data management solution helps ensure that trials meet the increasingly strict standards of regulators [1].

What are the basic features of EDC systems?

EDC systems usually include three basic features. Let’s review them.

eCRF Design. EDC systems have several design options for creating eCRFs. In format, eCRFs are similar to paper CRFs. Edit checks can be placed in the fields limiting what is entered to realistic and valid data. This is a safeguard against human error and helps ensure compliance with regulations. 

Query Management. An EDC system provides streamlined communication between monitors, data managers and clinical research coordinators. Data monitors and managers can send queries to clinical research coordinators and coordinators can respond within the EDC system. The data can be prevented from locking until all queries are responded to and resolved. 

Data Export. A data export system allows data managers to pull data out of the system and send it to a new location for further analysis. 

What advanced features can be included in an EDC?

Today, EDC systems can include features that go beyond basic database functionalities to incorporate mechanisms that assist with many more aspects of data management and analysis in clinical trials. 

As the software of EDC systems has developed, features have expanded to include randomization, supply management, adverse event reporting, coding, and progress reports. 

EDC systems can also be built with the ability to import electronic data quickly and reliably from outside sources so that lab reports, medical imaging files, and electronic health record information, for example, can be easily added to the eCRF. These additional features are key to meeting the ever more complex clinical trial requirements. 

Here is an example of how advanced functionalities can streamline data management while also sharpening accuracy:  

During clinical trials, regulatory agencies require that adverse events be coded according to the MedDRA dictionary and that medications be coded according to the WHO Drug dictionary. In a basic EDC system, this would be done manually by entering the source terms in free text with specialist medical professionals performing the coding. This not only involves a lot of tedious labor, but more important for complying with trial regulations, these professionals must ensure consistent and accurate decisions based on the content of the source term, any relevant related data, and the prior decisions for the trial. An EDC with advanced features provides tools to help streamline this coding and ensure accuracy and consistency.

What should you look for in an EDC system?

What you need and want in an EDC system will depend on the nature of the clinical trial. However, as the market has grown, there are a variety of new and established software providers of EDC systems. 

Many of these providers offer specialized solutions targeted to certain kinds of clinical trials or study phases. Increasingly, EDC systems include features such as cloud data storage, role-based permissions, clinical trials analytics, interactive dashboards, and electronic medical record data integration, but the exact features available will vary among software providers. 

Can EDC systems be purchased off the shelf?

Although software providers offer various unique EDC solutions, each EDC system must be individually built for a specific trial following the protocol of that trial.

Building an EDC system involves developing the system specifications and then creating the software system itself accordinglyimplementing, testing, and validating the data forms and fields.  

The specifications for the EDC system are developed from the Data Management Plan and the annotated CRF document, which should be approved by the clinical trial sponsor before an EDC system can be implemented.

Are there any regulations that apply to EDC systems?

In the United States, the Food and Drug Administration (FDA) has established regulatory requirements for EDC systems as part of its requirements for electronic records. EDC systems used in clinical trials must meet the regulations contained in Title 21 CFR Part 11 [2].

These regulations are designed to ensure the quality, accuracy, and integrity of data stored in the electronic systems, as well as the privacy protections for participants. To comply with FDA regulations, EDC systems must have the following in place:

  • User authorization controls: Security measures to identify accessing the application and entering the data, with controls to prevent unauthorized access to the system. 
  • Audit trail controls: Measures to ensure that the system keeps a record of the sources of the data, i.e. who made changes, when, and what information was changed. 
  • Attributability controls: Measures to ensure that when data is retrieved all information regarding each subject in a study is attributable to that subject. 
  • Data validation controls: Automatic or periodic checks performed by the computerized systems to ensure the validity and quality of clinical information. 
  • System integrity controls: periodic back-ups that prevent data loss. 

Additionally, EDC systems must have the following mechanisms to ensure data security and traceability: an internal clock (date and time), an access control module, and an activity registry. These three functionalities work together to track who is entering what data and when across the system. 

How do EDC systems help with clinical trial regulation compliance?

One of the principal reasons most researchers have switched to an EDC system is compliance. Clinical research is highly regulated, and regulations around data, identity, and privacy have become very complex and strict.

When capturing data using paper, or widely available applications such as Microsoft Excel, Microsoft Access, Google Forms or similar, it is extremely difficult to comply with all mandatory quality demands. In the current regulatory environment, using a single, specialized platform for data management is critical to ensure the trial complies with applicable regulations ranging from the European GDPR to the United States FDA regulations. 

Most legacy software applications are not equipped with the features needed to meet regulatory requirements such as audit trails, user access rights, and data encryption. Excel files, for example, can be copied and stored on a personal computer or other device, failing to meet even the basic threshold of security requirements. While basic paper-based systems are still permitted legally, it is difficult to manage clinical trial data “the old-fashioned way” and ensure all quality requirements.

By contrast, EDC systems allow on-demand data reporting and access while providing meticulous data security, automatic backups, and many safeguards to help trials comply with regulations. 

What EDC system solution does Zlynger offer?

Zlynger has developed an innovative web-based EDC solution that streamlines data collection, cleaning, and exports in phase I-IV clinical trials. This software tool does not require any installation in the computer and works in most Internet browsers and mobile devices. Zlynger’s EDC application enables secure, fast, and simple clinical data entry and processing for trials of any size and therapeutic area.

If you need an EDC system for data collection, please contact us at


[1] David B. Fogel, Factors associated with clinical trials that fail and opportunities for improving the likelihood of success: A review