eCOA and ePRO software, built and managed by experts

Capture patient (ePRO), observer (ObsRO), and clinician (ClinRO) outcome data in real time, from patients’ own devices first. Castor builds and manages the study for you and integrates with any major EDC, so eCOA runs as an expert-backed service, not another system you have to hold together.

Countries with Castor ePRO studies to date
+ countries
Supported with patient-reported outcomes to date
M+ participants
error rate post-validation
% compliance

Trusted by medical device companies, pharma sponsors, and outcomes research teams worldwide

 
 
Problem to solution

What changes when eCOA and ePRO run as one managed program

Traditional eCOA and ePRO setups leave teams carrying fragmented capture and unsupported builds. Here is what each problem becomes on Castor.

01

eCOA bolted onto your EDC
Integrates with any major EDC

eCOA and ePRO data flows to your existing EDC environment, whichever vendor you run, with one audit trail on the Castor side. No rip-and-replace required.

02

Compliance risk at the patient level
92% average patient compliance

Consumer-grade ePRO on patients’ own devices sustains 92% average compliance across Castor studies, instead of the completion gaps and recall bias that come with paper diaries and clunky apps.

03

Localization burden
Multilingual, validated capture

Castor captures patient data multilingually across web ePRO and the patient app, with a library of validated instruments, so global trials run in patients’ own languages.

04

Slow start-up
UAT in 4-8 weeks, managed for you

With managed Professional Services, builds reach UAT in 4-8 weeks for low-to-medium complexity and 8-12 weeks for high complexity (kickoff to UAT), ahead of the legacy industry average of 10-14 weeks and without cutting QA corners.

How Castor helps

What eCOA teams use Castor for

Six capabilities that turn patient-reported and clinician-reported data into clean, decision-ready evidence.

Works with any major EDC

eCOA and ePRO integrate with your existing EDC environment, whichever vendor you run. Patient-reported and clinician-reported data lands in real time, with one audit trail on the Castor side.

No rip-and-replace, and cleaner data at lock.

Consumer-grade BYOD app

App-based and browser-based capture on patients’ own devices, with provisioned devices where needed.

Lower provisioning cost and burden, higher completion.

Validated instrument library

Common instruments are available in the library, and Castor’s Professional Services team manages the scale licensing and validation, so you do not navigate instrument copyright and licensing hurdles yourself.

Faster build with the licensing work handled for you.

Built for global trials

Multilingual patient-facing capture across web, app, SMS, and messaging apps such as WhatsApp and WeChat, with study surveys buildable in any language and local server hosting in Australia. See the global infrastructure section below.

Global reach without rebuilding for every market.

Real-time monitoring and alerts

Live compliance dashboards and configurable alerts flag low completion and missing data as it happens.

Catch problems while you can still act, not at database lock.

AI across the eCOA build lifecycle

AI-enabled study builds and AI-enabled electronic migration of validated instruments accelerate setup, complex visit scheduling is handled in the build, and time-travel functionality lets testers simulate future visit windows during UAT instead of waiting for them in real time.

Builds and UAT measured in days, not calendar cycles.

Built for your trial

eCOA built around how your team actually runs trials

Two sponsor types, two different priorities. Castor runs eCOA, ePRO, ObsRO, and ClinRO as one managed program for both.

Biotech, Phases I to III

A safety net after go-live, not just software at go-live

Small and mid-size biotech teams often go live on a platform and then find themselves on their own when a protocol amendment lands or a mid-study change is needed. Castor bundles Data Management with eCOA, so the same team that builds your study stays with it.

Castor manages the build, handles mid-study changes, and locks your data on time. You get experienced study builders on your side through the whole trial.

The point is simple. You are not left to fend for yourself after go-live.

MedTech and EU MDR PMCF

Registry-scale follow-up for post-market clinical follow-up

EU MDR Post-Market Clinical Follow-up needs long-term safety and performance data from large patient populations, often for years after the device is on the market. Castor combines registry scale, digital physician surveys (ClinRO), and long-term patient follow-up (ePRO) in one study.

Clinicians complete structured assessments through digital eCRF surveys, and patients report outcomes from their own devices over time. You capture the long-term evidence PMCF requires without overburdening your sites.

One platform for the physician-reported and patient-reported data your PMCF plan depends on.

What you get either way

The same platform capabilities back up both, with specific proof you can check.

  • Integrates with any major EDC

    eCOA and ePRO results flow to your EDC environment, whichever vendor you run, and everything on Castor shares one audit trail. See how Castor compares on the Why Castor hub or in an independent eCOA software comparison.

  • Rated strongly for customer loyalty.

    Rated strongly for customer loyalty in ISR’s 2025 eCOA/ePRO Benchmarking.

  • Managed Professional Services.

    Castor builds your study, handles mid-study changes, and supports your team from kickoff through database lock.

eCOA as a service

An expert team behind every eCOA study

Castor eCOA is a service-based offering, not software handed over at go-live. The Professional Services team carries the specialist work that usually lands on your study team.

Managed study build

Experienced builders take your protocol from kickoff to UAT in 4-8 weeks for low-to-medium complexity builds.

Your team reviews and approves instead of building.

Scale and dimension management

Licensing, validation, and version control of assessment scales and their dimensions, handled by people who do it every week.

No copyright and licensing maze to navigate yourself.

Translation and localization management

Instrument translations and localized study surveys are coordinated for you across the markets your protocol covers.

Global studies without a translation project on the side.

Device provisioning and logistics

BYOD first, with provisioned devices sourced, configured, and shipped where patients need them.

Every patient can participate, own device or not.

Mid-study changes

Protocol amendments and schedule changes are implemented by the same team that built the study.

Amendments become days of work, not a renegotiation.

Direct-to-patient support

Tier-1 patient technical support is available as an optional, scoped service, with regions and languages set by what the study requires.

Patients get help without your sites becoming the helpdesk.

eCOA and ePRO explained

eCOA vs ePRO: what is the difference?

eCOA (electronic clinical outcome assessment) is the broad category for collecting clinical outcome data electronically. It covers four assessment types: patient-reported (ePRO), clinician-reported (ClinRO), observer-reported (ObsRO), and performance outcomes (PerfO). ePRO is the subset of eCOA reported directly by patients, such as symptom severity, quality of life, and treatment side effects.

When to use eCOA

Use eCOA as the umbrella when your protocol mixes patient, clinician, and observer assessments.

ObsRO covers data reported by a caregiver or guardian, and ClinRO covers structured clinician assessments where the protocol requires them. The observer and clinician reporting section below covers both in depth.

When to use ePRO

Use ePRO specifically when the endpoint is reported directly by the patient with no clinician interpretation.

Symptom diaries, quality-of-life measures, and treatment side-effect reporting are the most common ePRO endpoints, captured on the patient’s own device.

DimensioneCOAePRO
What it isThe broad category for electronic outcome assessmentA subset of eCOA reported directly by patients
Who reportsPatients, clinicians, observers, or performance tasksPatients only
Assessment typesePRO, ClinRO, ObsRO, PerfOPatient-reported only
Typical useMixed-source endpoints across a protocolSymptom, quality-of-life, and side-effect endpoints
On CastorNative ePRO, ObsRO, and ClinRO in one system that integrates with your EDC. PerfO results, such as a 6-minute-walk-test output, are captured through flexible eCRFs.Captured BYOD, in real time, by the patient

On Castor, ePRO, ObsRO, and ClinRO run in one system, so patient, caregiver, and clinician data share one audit trail, and results flow to your EDC environment whichever vendor you run. Performance outcome results are entered by site staff through eCRFs. For a deeper primer, read the eCOA and ePRO 101 guide.

ePRO in clinical trials

ePRO, defined

ePRO (electronic patient-reported outcome) is a subset of eCOA that captures outcomes reported directly by patients, such as symptom severity, quality of life, and treatment side effects. ePRO data is collected directly from the patient without clinician interpretation.

ePRO matters most where the patient’s own experience is the endpoint: oncology quality-of-life measures, rare disease symptom diaries, and ecological momentary assessment. Castor captures all of it BYOD, in real time, against a library of validated PRO instruments.

Castor ePRO solutions

Castor ePRO runs as part of one eCOA system, so patient-reported data lands alongside observer and clinician assessments in real time.

  • BYOD ePRO on patient devices.

    App-based and browser-based capture through the Castor patient app and the web that meets patients where they are.

  • Validated PRO instrument library.

    EQ-5D, FACT-G, SF-36, PROMIS and more, ready to deploy from the validated instrument library.

  • Real-time ePRO compliance monitoring.

    Live dashboards and alerts surface low completion while you can still act.
  • Multilingual ePRO across capture modalities.

    Global reach without rebuilding for every market.

Electronic capture reduces recall bias and missing data compared with paper diaries, and ePRO that runs inside your eCOA system avoids the reconciliation that comes with a standalone bolt-on tool.

eCOA beyond ePRO: observer and clinician reporting

Many protocols need more than patient self-report. Castor captures the other clinical outcome assessment types natively, inside the same study.

ObsRO for caregivers and guardians

When the patient cannot reliably self-report, observer-reported outcomes route the instrument survey to a caregiver or guardian. This is common in pediatric, CNS, and dementia trials, where a parent or care partner records behavioral and cognitive change. ObsRO runs natively on Castor alongside patient ePRO.

ClinRO for site clinicians

Clinician-reported outcomes are captured through the EDC and CDMS as specialized eCRFs and digital physician surveys, completed by site staff at the bedside or during a televisit. This is central to EU MDR post-market clinical follow-up studies, where the clinician assessment is the endpoint. ClinRO is part of the same database and audit trail as ePRO and ObsRO.

Global infrastructure

eCOA that runs where your patients are

Global trials need more than translation. They need local infrastructure your patients and sites can actually use.

Multilingual patient capture

Patient-facing capture is multilingual across the patient app, web ePRO, SMS, and messaging apps such as WhatsApp and WeChat, and study surveys can be built in any language, so data quality does not drop outside English-speaking markets.

Direct-to-patient support, scoped per study

Tier-1 patient technical support is available as an optional, scoped service, with the regions and languages set by what the study requires.

Native WeChat eCOA for trials in China

For studies running in China, patients complete eCOA through native WeChat, the app they already use every day, instead of installing a separate clinical app.

Local server hosting in Australia

Local server hosting in Australia supports studies in the region and their data residency expectations, so nearby sites run on infrastructure close to home.

Proven outcomes

eCOA and ePRO outcomes on Castor

Platform scale and study-level results, each stated with its source.

M+ participants

supported with patient-reported outcomes to date, with 202 million+ ePRO datapoints captured globally

“Running our patient-reported outcomes on the same database as our EDC removed an entire reconciliation step. Our team sees compliance issues in real time instead of at lock.”

Innovation Project Manager, Top 10 large pharma

Average patient compliance across Castor studies. A portfolio-level figure, not a single-study best case.
% compliance
Caregiver-reported (ObsRO) behavioral and cognitive data captured in a single real-world study. A study-level result, not a portfolio average.
+ patients

Time to value

Builds reach UAT in 4-8 weeks for low-to-medium complexity and 8-12 weeks for high complexity with managed Professional Services, ahead of the legacy industry average of 10-14 weeks.

Therapeutic area experience

eCOA and ePRO depth across therapeutic areas

Castor supports patient-reported and caregiver-reported endpoints across the areas where they matter most.

Oncology

Oncology trials

ePRO for quality-of-life endpoints and complex assessment schedules across long oncology protocols.

Learn more

Rare disease

Rare disease trials

Symptom diaries and patient-reported endpoints for small, dispersed rare disease populations.

Learn more

CNS and neurology

CNS and neurology trials

High ePRO burden and caregiver-reported ObsRO assessments, delivered through a patient-friendly BYOD experience.

Learn more

Cardiovascular

Cardiovascular trials

Patient-reported data at scale across large, multi-site cardiovascular and vascular studies.

Learn more

Infectious disease

Infectious disease trials

Decentralized capture and remote ePRO for fast-moving infectious disease programs.

Learn more

Obesity and metabolic

Obesity and metabolic trials

Longitudinal patient-reported outcomes for metabolic and weight-management studies.

Learn more

Independent review platforms

Rated by clinical researchers

Recognized by independent analysts

Rated strongly for customer loyalty in ISR’s 2025 eCOA/ePRO Benchmarking.

Common questions

Frequently Asked Questions

eCOA (electronic clinical outcome assessment) is the broad category for collecting clinical outcome data electronically. It covers four assessment types: patient-reported (ePRO), clinician-reported (ClinRO), observer-reported (ObsRO), and performance outcomes (PerfO). ePRO is the subset reported directly by patients. On Castor, ePRO, ObsRO, and ClinRO are captured natively in one system that integrates with your EDC, and performance outcome results are captured through flexible eCRFs.

ePRO (electronic patient-reported outcome) is a subset of eCOA that captures outcomes reported directly by patients, such as symptom severity, quality of life, and treatment side effects. ePRO data is collected directly from the patient without clinician interpretation.

eCOA refers to the electronic collection of clinical outcome data, replacing paper diaries and questionnaires. It covers four assessment types: patient-reported (ePRO), clinician-reported (ClinRO), observer-reported (ObsRO), and performance outcomes (PerfO). Electronic capture time-stamps each entry and reduces the transcription errors common to paper.

EDC (electronic data capture) is used by investigators and site staff to enter site-collected data. eCOA is used by patients, caregivers, or clinicians to capture outcome data, often between site visits. Castor eCOA integrates with any major EDC, so outcome data flows to your trial database without a separate reconciliation step.

Castor offers a library of validated instruments, including common measures such as EORTC, FACT-G, EQ-5D, SF-36, and PROMIS, plus therapeutic-area-specific instruments where they are used. Castor’s Professional Services team manages the scale licensing and validation, so you do not navigate the instrument copyright and licensing process yourself. Instruments can be deployed from the library rather than rebuilt for each study.

Yes. BYOD lets patients use their own smartphones, which reduces provisioning cost and improves compliance. It requires attention to device compatibility, version control, and data security. Castor supports both app-based and browser-based BYOD, with provisioned devices available where a patient has none.

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