REDCap Research Database: Setup, Export, and Use

A REDCap research database is a secure, metadata-driven web platform designed specifically for building and managing electronic data capture systems in clinical and translational research. Originally developed at Vanderbilt University in 2004, REDCap (Research Electronic Data Capture) provides research teams with autonomous control over study instruments, participant surveys, longitudinal schedules, and regulatory audit logging without requiring database programming expertise.

What it is used for in research

In academic and clinical environments, REDCap serves as an institutional solution for secure data collection, protocol compliance, and multi-site coordination. Unlike generic spreadsheet tools or commercial survey software, REDCap isolates data entry forms and study operations behind granular user permissions, automated data validation, and complete audit logging.

Primary research applications include:

• Clinical Trials and Interventional Studies: Managing multi-arm trials, tracking participant visit schedules, administering blinded treatments, and recording adverse events within an environment capable of meeting 21 CFR Part 11 technical controls. For broader study software architectures, see our guide to clinical data management tools.
• Observational Cohorts and Registries: Collecting longitudinal patient follow-up data across multiple clinic visits or yearly intervals using defined study events and repeating instruments.
• Electronic Data Capture (EDC): Serving as a dedicated institutional electronic data capture (EDC) system for investigator-initiated studies, patient registries, and biobanking specimen tracking.
• Participant Surveys: Administering public or individualized patient-reported outcome surveys via secure web links, automated email invitations, or SMS delivery.
• Multicenter Collaboration: Segmenting data access across hospital sites using Data Access Groups (DAGs), ensuring research personnel at a specific site access only their own enrolled participants while coordinating centers retain complete cross-site oversight.

Install or access (official source only)

REDCap is institutional server software; it is not distributed as a desktop program or standalone application for personal computers. Individual researchers access REDCap through an authorized web browser connected to their institution’s secure installation.

Access for Researchers

Researchers access REDCap by logging into their university, medical center, or research institute portal (typically authenticated via institutional Single Sign-On, LDAP, or Active Directory). Contact your local research informatics department, Clinical and Translational Science Award (CTSA) hub, or IT service desk to obtain an account, establish study ownership, or link an institutional Institutional Review Board (IRB) protocol.

Institutional Licensing and Installation

Institutions must follow official consortium procedures to deploy REDCap on local or cloud infrastructure:

• Consortium Licensing: The software is provided at no license cost to non-profit academic institutions, healthcare systems, and government agencies that formally join the REDCap Consortium hosted by Vanderbilt University. A software license agreement must be executed prior to obtaining access to the codebase on the REDCap Community portal.
• Server Operating System: Supported across Linux, Unix, Windows Server, and macOS environments. Production deployments typically utilize Enterprise Linux distributions (such as Ubuntu LTS, RHEL, or Rocky Linux).
• Web Server and PHP: Runs on Apache HTTP Server or Microsoft IIS. Requires PHP 8.1.0 or higher with essential extensions enabled, including cURL, OpenSSL, MySQLi, and mbstring. An SSL certificate is strictly required to enforce encrypted HTTPS communication.
• Database Server: Requires MySQL 5.5.5 or higher, MariaDB 5.5.5 or higher, or Percona Server. REDCap is incompatible with Microsoft SQL Server, PostgreSQL, or Oracle. Best practices dictate separating the web server and database server onto distinct physical or virtual hosts protected by network firewalls.
• Email Infrastructure: Requires connection to an institutional SMTP server or local SMTP relay to dispatch automated system alerts, password resets, and participant survey invitations.
• Cloud Deployments: Supported on Amazon Web Services (AWS) and Microsoft Azure using automated deployment templates (such as AWS CloudFormation and Azure Quick Start templates developed in collaboration with the REDCap Consortium). Organizations storing Protected Health Information (PHI) on cloud infrastructure must establish a Business Associate Agreement (BAA) with the cloud provider; review our detailed breakdown on REDCap HIPAA compliance requirements.

Step-by-step task

Follow these numbered steps to create, design, permission, and deploy a research database using the current REDCap web interface.

1. Create the Project:
   • Log in to your institutional REDCap portal and click the + Create New Project tab in the top navigation bar.
   • Enter the project title under Project title.
   • Select Research under Purpose of the project. Complete the required research metadata, including the Principal Investigator name, primary contact email, and IRB protocol number.
   • Under Project start options, select Start project from scratch (clean slate) or choose a pre-configured template from the template library. Click Create Project.
2. Configure Project Setup Dashboard:
   • Upon creation, REDCap opens the Project Setup checklist.
   • Under Main project settings, click Enable next to Use surveys in this project? if collecting data directly from study participants.
   • Click Enable next to Use longitudinal data collection with defined events? if participant data will be gathered repeatedly across distinct study visits (such as Baseline, Month 1, and Month 6).
3. Build Data Collection Instruments:
   • In the Project Setup checklist, locate the section titled Design your data collection instruments & check your data dictionary and click Online Designer.
   • Click Create a new instrument from scratch or edit the default first instrument (often labeled My First Instrument).
   • Click Add Field to insert variables. Choose appropriate field types: Text Box (with validation types such as Date [M-D-Y], Integer, Number, or Email), Notes Box, Drop-down List, Radio Buttons, or Checkboxes.
   • Define a unique, lowercase variable name in Variable Name (for example, sbp_baseline) and provide clear instructions in Field Label.
   • If a field collects direct patient identifiers (such as name, medical record number, date of birth, or phone number), mark Identifier? as Yes. This designation enables automated redaction during subsequent analytical exports.
   • For complex question flows, click the green branch icon to configure conditional display rules; for specific syntax and validation rules, consult our guide to REDCap branching logic syntax.
   • Alternatively, build instruments offline by downloading and editing the project spreadsheet via the Data Dictionary menu; learn more in our reference on data dictionaries in research data management.
4. Define Events and Designate Instruments (Longitudinal Projects):
   • If longitudinal data collection was enabled, return to Project Setup and click Define My Events under Define your events and designate instruments for them.
   • Create study events (e.g., Event 1: Screening, Event 2: Baseline, Event 3: Follow-up).
   • Click the Designate Instruments for My Events tab and check the corresponding grid boxes to indicate which instruments are completed at each scheduled visit.
5. Configure User Rights and Roles:
   • In the left-hand navigation panel under Applications (or from the Project Setup checklist), click User Rights.
   • Create standardized User Roles (e.g., Coordinator, Data Entry, Statistician).
   • Assign specific privileges for each role: toggle Project Design and Setup, User Rights, Data Logging, and instrument-level permissions (No Access, Read Only, or View & Edit).
   • Under Data Export Tool, restrict access to de-identified data or full data sets based on user necessity and IRB approval.
   • For multicenter studies, navigate to Data Access Groups under Applications to assign staff members to specific hospital sites.
6. Test in Development and Move to Production:
   • Enter test records using the Add / Edit Records link on the left sidebar to verify calculations, survey distribution triggers, and branching logic.
   • Return to Project Setup, scroll to the bottom, and click Move project to production.
   • Choose whether to delete all test records or retain existing records. Moving to production locks the project architecture to prevent accidental loss of live research data.
   • Once in production, future schema modifications must be made via Draft Mode, ensuring administrative review and schema validation before changes go live.

Output and how to read it

REDCap structures output files to maintain traceability between data entry forms, data dictionaries, and downstream statistical pipelines.

Export Formats and Statistical Packages

To generate data exports, navigate to Data Exports, Reports, and Stats under Applications on the left menu. Click Export Data next to an existing report or the All data row. REDCap provides five primary export pathways:

• Comma Delimited (CSV): Available as Raw data (numeric codes for categorical variables, e.g., 1, 2) or Labels (text values, e.g., Male, Female).
• Statistical Software Packages: Dedicated two-file downloads for R (data CSV + .r script), SPSS (data CSV + .sps syntax script), SAS (data CSV + .sas script), and Stata (data CSV + .do syntax file). The syntax scripts automatically map column types, assign variable labels, convert missing values, and define value labels matching the project data dictionary.
• CDISC ODM (XML): Clinical Data Interchange Standards Consortium Operational Data Model format (ODM 1.3 XML), supporting regulatory trial archiving and metadata exchange.
• PDF Documentation: Export of blank instruments or completed participant records with full audit histories.

Export De-Identification Options

During export generation, REDCap allows authorized users to apply automated de-identification controls:

• Remove Identifiers: Automatically strips all variables flagged as Identifier during instrument design.
• Hash Record ID: Replaces the primary participant identifier with an irreversible cryptographic hash string.
• Date Shifting: Shifts all project dates and timestamps by a consistent, randomly generated integer offset between 1 and 364 days per record. Date shifting preserves intervals between longitudinal visits, medication changes, and adverse event onset while masking real calendar dates.
• Remove Free-Form Text: Suppresses unvalidated text box and notes fields that might contain inadvertent protected health information.

Reading Export Schemas

Understanding the exported matrix depends on whether the study is configured as classic, longitudinal, or repeating:

• Classic Cross-Sectional Studies: Exported as a flat table with exactly one row per study record. The first column contains the primary key (e.g., record_id), followed by instrument fields. Each instrument automatically produces a trailing status variable named [instrument_name]_complete, where values represent completion states: 0 = Incomplete, 1 = Unverified, and 2 = Complete.
• Longitudinal Studies: Exported with multiple rows per participant record. Rows are differentiated by the system column redcap_event_name (the unique event label defined in the project setup). Variables not collected at a given event will contain missing values for that row.
• Repeating Instruments: Repeated instances of surveys or data collection forms produce separate rows containing redcap_repeat_instrument (identifying the repeating form) and redcap_repeat_instance (a sequential integer starting at 1).

Troubleshooting

Common operational issues encountered during REDCap database development and production maintenance:

Issue	Underlying Cause	Resolution Step
Data Dictionary upload rejected	Formatting syntax errors in select_choices_or_calculations, invalid characters in field_name, or missing required CSV headers.	Ensure choice options use the exact format code, label separated by a pipe character (e.g., 1, Yes | 2, No). Variable names must be lowercase alphanumeric with underscores only, starting with a letter. Check that the file is saved as a standard comma-separated CSV.
Branching logic not displaying fields	Syntax errors in conditional expressions, missing square brackets around variable names, or incorrect choice quotation.	Enclose all variable names in square brackets and choice codes in single quotes (e.g., [smoking_status] = '1'). For multiple conditions, use explicit uppercase boolean operators: [age] >= 18 AND [consent_given] = '1'.
“Erase Current Value” alert appears during data entry	A user modified an upstream field, causing downstream branching logic to evaluate to false while the dependent field already holds saved data.	Instruct data entry staff that hiding a previously answered field prompts REDCap to either retain hidden data or erase it. Review workflow procedures to ensure screening criteria are finalized before dependent instruments are completed.
Changes blocked in Production status	The project is in production, preventing direct edits to existing instruments to protect data integrity.	Navigate to Online Designer or Data Dictionary and click Enter Draft Mode. Make required additions or label adjustments. When finished, click Submit Changes for Review. Non-critical modifications are often auto-approved, while alterations that could delete existing data require local REDCap Administrator approval.
Statistical script import fails in R or SPSS	CSV file path not updated in the script, or special characters corrupted by character encoding discrepancies.	Open the .r, .sps, or .sas script in a text editor and update the file path reference on the first lines to point to the exact local directory where the accompanying CSV file is saved. Verify that the CSV file was saved using UTF-8 character encoding.

Free alternatives

When selecting data collection software, research teams evaluate platforms based on licensing costs, server requirements, regulatory validation capability, and field mobility. The table below compares REDCap with established free and open-source alternatives used in academic and field research:

Software	License / Cost Model	Hosting & Architecture	Clinical Trial & PHI Suitability	Offline Mobile Support	Primary Research Use Case
REDCap	Free institutional license for non-profit consortium partners	Institutional self-hosted server (Linux/Windows, Apache/IIS, PHP 8.1+, MySQL/MariaDB) or cloud (AWS/Azure)	High; supports HIPAA, FISMA, and 21 CFR Part 11 electronic records with LTS validation scripts	Yes; REDCap Mobile App (iOS/Android) and MyCap participant-facing app	Clinical trials, hospital registries, translational studies, and multi-site academic protocols
KoboToolbox	Open-source (GPL-3.0); free public servers for humanitarian/academic use or self-hosted	Cloud service or self-hosted Docker containers (Python/Django, PostgreSQL, MongoDB, Redis)	Moderate; suited for de-identified global health and survey research; not natively 21 CFR Part 11 validated	Yes; KoboCollect (Android) and web-based Enketo web forms for offline caching	Global health field studies, epidemiology surveys, disaster response, and socio-economic evaluations
ODK Central (Open Data Kit)	Open-source (Apache 2.0); free self-hosted community edition	Self-hosted Docker deployment (Node.js, PostgreSQL, Nginx)	Moderate; robust access controls but lacks FDA Part 11 audit and electronic signature workflows	Yes; ODK Collect (Android) with extensive offline media, GPS, and sensor integration	Field biology, ecological mapping, remote longitudinal cohort tracking, and mobile survey collection
LimeSurvey	Open-source (GPL-2.0) Community Edition; paid cloud hosting available	Self-hosted web server (Apache/Nginx, PHP, MySQL/PostgreSQL/MSSQL)	Limited for clinical trials; designed for general survey workflows rather than clinical EDC or patient registries	Limited; web-responsive forms (third-party offline caching plugins required)	Academic social science questionnaires, institutional feedback, course evaluations, and psychology experiments

FAQ

Is REDCap free for research studies?

Yes, REDCap software is provided at no license cost to non-profit academic institutions, medical centers, and government research bodies that join the global REDCap Consortium. However, institutional IT departments allocate resources to host, secure, back up, and maintain the server infrastructure and local administrative support.

Can REDCap be installed on a local laptop or personal workstation?

No. REDCap is enterprise web-server software built using PHP and MySQL. It must be deployed on a centralized local or cloud server managed by institutional IT personnel to ensure system security, automated backups, encrypted access, and audit trail reliability.

What is the difference between Development and Production status in REDCap?

In Development status, researchers design forms, modify fields, and test data workflows without restriction. Moving to Production status locks the database schema to protect collected study data. Once in Production, instrument modifications must be executed through Draft Mode, preventing accidental deletion of variables or alteration of existing categorical codes.

How does REDCap protect Protected Health Information (PHI) during export?

During instrument design, variables that record patient identifiers are flagged as Identifiers. When exporting data through the Data Exports, Reports, and Stats module, researchers can select automated de-identification controls that strip all tagged identifier fields, hash participant record IDs, date-shift all longitudinal visit timestamps, and remove unvalidated free-text notes fields.

Can researchers modify instruments after a study enters Production?

Yes, using REDCap’s Draft Mode. Within Draft Mode, researchers add new variables, alter field labels, or insert additional instruments without disturbing live data entry. Before changes are committed, REDCap automatically evaluates the modified schema; changes that risk deleting existing data or corrupting categorical codes generate critical warnings and may require administrative verification before deployment.

Sources

• Project REDCap. Software Overview and Core Platform Features. Vanderbilt University. URL: https://projectredcap.org/software/ (verified 2026-11-08).
• Project REDCap. Installation & Technical Requirements. Vanderbilt University. URL: https://projectredcap.org/software/requirements/ (verified 2026-11-08).
• Project REDCap. About the REDCap Consortium and Platform Evolution. Vanderbilt University. URL: https://projectredcap.org/about/ (verified 2026-11-08).
• Harris PA, Taylor R, Thielke R, Payne J, Gonzalez N, Conde JG. Research electronic data capture (REDCap)—A metadata-driven methodology and workflow process for providing translational research informatics support. Journal of Biomedical Informatics. 2009;42(2):377-381. doi:10.1016/j.jbi.2008.08.010. PMC2700030.
• Harris PA, Taylor R, Minor BL, et al. The REDCap consortium: Building an international community of software platform partners. Journal of Biomedical Informatics. 2019;95:103208. doi:10.1016/j.jbi.2019.103208.