ePRO is how participants report symptoms, function and experience directly into the study record, usually on their own phone. This guide covers what it is, which instruments it carries, what regulators care about, how it differs from eCOA and how to adopt it. It is an explainer; the product pages cover specific features.
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Did pain limit your usual activities?
Time you took your study medication
ePRO in brief
Definition
A patient-reported outcome (PRO) is information about how a person feels or functions that comes straight from them: pain intensity, fatigue, sleep, mood, symptom frequency, quality of life, or whether they took a dose. PROs matter because many outcomes that count to patients cannot be seen on a lab test or scan. ePRO means gathering them with an electronic tool instead of paper.
That tool can be a smartphone web page, a tablet handed out at a visit, a provisioned device or a dedicated app. Participants answer questions, the system time-stamps and stores the answers, and the study team sees the data in near real time. A good ePRO setup is scheduled (a daily diary, a weekly questionnaire, a visit-based scale), prompted (reminders when something is due) and tied to the participant's record in the study database.
Words used loosely in this field include ePRO, eCOA, eDiary and PRO. They overlap. For the relationship between the main terms, see eCOA software for clinical trials, and for a sibling concept in the glossary, ClinRO, ObsRO, PerfO and PRO.
Terms
| Term | Who reports | Typical example |
|---|---|---|
| PRO / ePRO | The participant | Pain scale, fatigue questionnaire, symptom diary |
| ClinRO / eClinRO | A clinician after assessing the participant | Clinician-rated severity scale |
| ObsRO / eObsRO | A caregiver or other observer | Parent-reported seizure or behaviour log |
| PerfO | The participant performing a standardised task, scored by a rater or device | Timed walk or cognitive test |
| eCOA | Umbrella term for all of the above, collected electronically | Any mix in one study |
| eDiary | The participant, repeatedly | Daily symptom or medication log |
Check the exact terms used by your regulator or sponsor. Capture supports participant questionnaires and site-completed forms on the same platform.
How it works
The sequence is similar in most systems. The team chooses or builds the instrument, sets a schedule, decides how participants receive and answer tasks, and monitors completion. The data flows into the same database as the clinical data so that analysis, queries and exports use one record.
Many named questionnaires are licensed or have terms of use, so confirm the permission to use and to implement electronically before you build. The study keeps the licence with its documents.
Wording, response options and recall period should be reproduced faithfully. Where the rights holder offers an electronic version or guidance for migration, follow it. Capture lets a study team record licence details on a patient questionnaire and does not verify licences or supply licensed instrument text.
Moving a paper instrument to a screen can change how people answer, for example through scrolling, one item per screen or different layouts. Good practice is to assess whether the electronic version measures the same thing, with the depth of testing depending on how much the migration changes the instrument. Read the rights holder's guidance and published recommendations on migration before you start, and ask your biostatistician how the endpoint will be analysed.
Compliance is the practical risk: a diary is only as good as the proportion completed on time. Features that help include sensible task windows, clear reminders and a short, easy form. See ePRO compliance and diary completion rates for what moves completion.
Options include participants using their own phone (bring your own device), provisioned devices or site tablets. Bring your own device is cheaper and reaches more people but requires thought about accessibility and equal access. See BYOD ePRO without an app download.
Create a questionnaire, set a schedule and fill it in as a participant would. The free sandbox has every feature, with no credit card and no time limit.
Regulation
There is no single "ePRO regulation". Several sources apply together. In the United States, FDA's guidance "Patient-Reported Outcome Measures: Use in Medical Product Development to Support Labeling Claims" (final, December 2009) describes how FDA reviews PRO instruments. It is non-binding, and it addresses how instruments are developed and, for electronic ones, concerns including the investigator's control of and access to the electronic source records and database security. FDA also publishes patient-focused drug development guidance; check the current set.
Electronic records and signatures are covered by 21 CFR Part 11 for FDA-regulated studies, with FDA's October 2024 Q&A on electronic systems, records and signatures in clinical investigations as the current explanatory text. In the EU, the EMA guideline on computerised systems and electronic data in clinical trials covers audit trails, access control and archiving. ICH E6 sets the good clinical practice baseline. Read Annex 11 vs 21 CFR Part 11 for a comparison.
In practice, expect to show: the instrument and its permission to use, how participant identity and data entry are controlled, that data are time-stamped and attributable, that the study team can access the source data, that changes are audited and that data survive for the retention period. This is general information, not legal advice.
Adoption
Tie each PRO to an endpoint or safety need. Cut anything that is not needed; every question is a burden.
Pick validated instruments where they exist and confirm licensing. For custom diaries, keep wording simple and pilot them. Pre-built diary templates in the template library can be a starting point.
Decide task windows, reminder timing, how missing entries are handled and what is shown to the participant.
Own phone, site tablet or provisioned device. Check accessibility and consider paper back-up where your design allows it.
Complete the whole schedule in a sandbox on a real phone and review the export. Include a person who is not on the study team.
Review completion during the study and act early on gaps with a call or a reminder. See ePRO software for clinical trials.
In Capture
Capture runs ePRO in the same platform as EDC and eConsent, so participant questionnaires and site forms share one audit trail. The Capture ePRO page describes the product. Briefly: the study team builds a questionnaire with ten question types (text, numeric, linear scale, slider, single choice, multiple choice, dropdown, date, time and long text), schedules it by visit or diary, and participants answer on their own phone from a link with no app install. Email reminders are available, and a set of diary templates (sleep, pain, mood, fatigue and others) is in the template library.
Capture does not supply licensed instrument wording, and patient questionnaires carry optional licence-record controls. If you plan multilingual questionnaires, confirm the current status with the team before relying on it.
ePRO stands for electronic patient-reported outcome: information about health or function reported directly by the participant and collected electronically.
eCOA is the broader term for clinical outcome assessments collected electronically, including patient-, clinician-, observer-reported and performance outcomes. ePRO is the patient-reported part.
Electronic collection can time-stamp entries, send reminders, prevent skipped items and remove transcription, which are common weaknesses of paper. It still needs good design and a plan for participants who cannot use it.
For FDA-regulated studies, electronic records and signatures are expected to meet Part 11 controls such as access control, audit trails and attributable entries. Capture provides Part 11-aligned controls; validated use is shared with the sponsor.
Not necessarily. In Capture, participants complete questionnaires on their own phone from a link without installing an app. Other systems use apps or provisioned devices.
Often yes, but you need permission from the rights holder and the electronic version should keep the instrument's meaning. Follow the rights holder's migration guidance.
Keep the questionnaire short, set sensible windows, send timely reminders, test on real phones and review completion early so you can follow up quickly.
Keep exploring
Capture ePRO
Product page.
ePRO software for clinical trials
Buying view.
eCOA software for clinical trials
Broader term.
ePRO compliance and diary completion rates
Completion.
BYOD ePRO without an app download
Own device.
Best ePRO software
Shortlist.
ClinRO, ObsRO, PerfO and PRO
Glossary.
Template library
Diary templates.
Free sandbox with every feature. No credit card, and you pay only when you go live with real participants.