Where studies actually fail
EDC-first platforms automate forms. Delve recovers patients.
Castor's EDC core is excellent for designing CRFs, eCOA forms, and randomization workflows quickly — especially in academic, biotech, and investigator-initiated trials where flexibility matters. But the deeper challenge in modern studies isn't building the form. It's whether a real patient — wearing a device, in their home, in their language — actually completes it for 12 weeks. That's a different problem, and it's Delve's home turf.
- Open, configurable EDC for academic and biotech studies
- Fast study build with eCOA / ePRO / eConsent modules
- Investigator-initiated and federally-funded research
- Cost-effective for smaller cohorts
- Reasonable randomization & supply management
EDC and data capture. Real value.
- A patient who hasn't worn their device for 3 days
- A wearable producing physiologically implausible data
- An eCOA diary missed in a language the patient speaks at home
- A caregiver overwhelmed in a rare-disease trial
- Endpoint integrity when devices have firmware drift
Patient-facing, cross-cultural, real-world. Castor Catalyst can speed study build, but it can't recover a drifting patient.
- 70+ validated wearable algorithms
- 7-dimension real-time compliance scoring
- Concierge-as-a-Service in 120+ languages
- 92–98% per-study eCOA/ePRO completion
- Up to 63% retention uplift in long-duration cohorts
- UI-driven multi-tenant rollout (US/NA, EU, LATAM, APAC, MENA) — no IT tickets, no per-region procurement
- Open endpoint APIs — REST + webhooks + CDISC + Parquet delivery into your EDC and analytics stack, with versioned contracts and provenance
Platform-owned outcomes. Documented per study.
Bottom line: Castor's irreducible strength is academic and investigator-initiated research economics — the Site License model for IITs and the “For Impact” free-access program. If your study is academic or non-industry, Castor is purpose-built for it. For every other category — biotech, pharma-sponsored, wearable-heavy, multilingual, long-duration, or any study where compliance and retention are deliverables rather than aspirations — Delve offers the same eCOA / ePRO / eConsent core plus a 70+ validated wearable algorithm library, Concierge-as-a-Service in 120+ languages, and platform-owned 92–98% completion outcomes that Castor doesn't compete on.
How Delve actually delivers 92–98% completion
Three engagement layers, not one
Other platforms bet on a single approach: configurable software (YPrime), AI agents (Medable), rater services (Signant), or core-lab pedigree (Clario). Delve combines three engagement layers on top of one validated wearable platform — which is why per-study completion lands at 92–98% vs. the published industry baseline of 80–90%.
Fully featured eCOA you can build any study on. Configurable without engineering tickets.
- Branching logic, edit checks, scheduling, scoring, version control
- Validated PRO / ClinRO / ObsRO / PerfO instrument support
- Pre-built diary templates + form builder for custom protocols
- 120+ language delivery, BYOD or provisioned devices
- UI-driven multi-tenant rollout (US/NA, EU, LATAM, APAC, MENA)
Engagement before patients drift. Built into the platform — not a separate product to license.
- Smart push notifications & configurable reminders
- Adaptive UX that responds to completion patterns
- Multimedia guidance (video, audio, visual prompts)
- Patient app with centralized "For You" task view
- Multilingual prompts in the patient's preferred language
When tech engagement isn't enough — humans recover the patient before data goes missing.
- 120+ languages of trained human concierge
- Documented <24h response windows
- Watch-level alerts triaged before they reach sites
- Caregiver support for rare-disease & pediatric trials
- Device troubleshooting, re-engagement, escalation
Why this combination works: Configurable software alone produces blank forms patients ignore. Engagement alerts alone produce notification fatigue. Human concierge alone is expensive and doesn't scale. The three together, operating on one validated wearable platform, are what produce 92–98% completion in real studies. Every other vendor in this comparison provides one or two of these layers — not three.
Two different bets
EDC-with-eCOA bolt-on, or compliance-and-retention operating system?
Both platforms can run a hybrid trial. The difference shows up in who owns the work of keeping patients in the study, validating wearable endpoints, and recovering compliance when it starts to drift.
Castor and Delve solve different problems
- Castor's pitch: Open Clinical Data Platform with EDC, eCOA/ePRO, eConsent, and DCT modules. Used by 500+ customers across 100+ countries, ~4,000 active studies. Best-fit for academic and investigator-initiated research where economics drive vendor selection.
- Castor's 2026 bet: “Self-driving clinical trials” via Castor Catalyst (launched October 2025, built on Google Cloud Vertex AI / Gemini). Targets a ~50% manual-effort reduction in Phase 2/3 study setup. Public Catalyst deployment evidence is currently limited to Castor's own Omnia / BEACON pilot — sponsors evaluating Castor should ask for named production-scale references outside the pilot.
- Delve's strength: 70+ validated wearable algorithms on a harmonized clinical data layer, plus Concierge-as-a-Service in 120+ languages — both owned as platform-delivered compliance and retention outcomes.
- Delve's commitment: 92–98% per-study completion ranges and up to 63% retention uplift in long-duration cohorts, documented per study.
- Castor Catalyst is impressive for automating study build and data ingestion; it is not a wearable algorithm library or a human concierge layer. For wearable-heavy, multilingual, or long-duration protocols, those gaps matter.
Delve-documented eCOA/ePRO completion range, per study.
Up to 63% retention uplift in long-duration cohorts (Delve).
Validated digital-endpoint algorithms across 25+ wearables.
Languages of human concierge, built into the platform.
Where the two platforms genuinely overlap
At the feature checklist level, Castor EDC and Delve Health each support eCOA, ePRO, eConsent, and analytics. Either platform can run a modern clinical trial. Both platforms ship:
- Digital informed consent (eConsent) with multimedia and audit trail
- Electronic Clinical Outcome Assessment (eCOA) and patient-reported outcomes (ePRO)
- Wearable and digital health technology integration
- Real-time analytics dashboards for study oversight
- Decentralized and hybrid trial design support
- Full compliance posture: HIPAA, GDPR, 21 CFR Part 11, ICH GCP, ISO 27001
The differences show up only once you ask what happens when compliance starts to drift, when a wearable produces unusable data, or when sites need relief.
Side-by-side comparison
Castor EDC vs Delve Health: capability comparison
The table below reflects publicly documented capabilities and standard delivery models for each platform. Specific configurations may vary by contract.
| Capability | Castor EDC | Delve Health |
|---|---|---|
| Outcomes — where studies live or die | ||
| Per-study completion rate accountability | Customer-driven | 92–98% documented per study |
| Retention uplift target | Customer-driven | Up to 63% in long-duration cohorts |
| Validated digital-endpoint algorithms | EDC-focused; few wearable algorithms | 70+ algorithms across ECG, glucose, activity, sleep, frequency & QC |
| Real-time compliance scoring | EDC monitoring dashboard | 7-dimension hourly readiness + closed-loop recovery |
| Human concierge patient support | Customer / partner-delivered | Built into platform — 120+ languages, <24h response windows |
| Wearable device support | Limited; partner-driven | 25+ devices on harmonized clinical data layer |
| Site burden reduction | Site dashboards | Concierge triages alerts before sites see them |
| Architecture & speed to launch globally | ||
| Multi-region tenant rollout | Multi-tenant SaaS, but tenant provisioning is vendor-managed | UI-driven multi-tenant — spin up region-aware tenants (US/NA, EU, LATAM, APAC, MENA) without IT tickets or per-region procurement |
| Diary & eCOA template library | CRF builder; no validated diary template library | Pre-built diary templates for rapid eCOA build, plus configurable form builder for custom protocols |
| Self-serve admin platform | Vendor-administered, ticket-based for changes | Admin UI for tenant management, user roles, audit log, diary template library |
| API & EDC / analytics integration | Open API for EDC core — strong for academic / integrator-led research; endpoint-API maturity less documented | Endpoint APIs with lineage — REST pull + webhook push + batch + CDISC packages + Parquet, with versioned contracts, provenance, audit trail and direct EDC delivery |
| Built-in audit log accessible to sponsors | Available on request from vendor | Live admin UI — sponsors and CROs can self-audit |
| EDC core — where Castor focuses | ||
| EDC data capture & CRF design | Yes — open, configurable EDC core | Partner integration |
| Randomization & trial supply (RTSM) | Yes — built-in | Partner integration |
| Academic / investigator-initiated focus | Yes — primary segment | Industry-sponsored studies |
| Open architecture / data export | Yes | Yes |
| Shared baseline | ||
| eCOA / ePRO platform | Yes | Fully configurable eCOA — adaptive UX, branching logic, multimedia, 120+ languages, validated PRO/ClinRO/ObsRO/PerfO instruments, version control without engineering tickets |
| Patient engagement model | Reminders & form completion; engagement is sponsor-managed | Multi-layered — smart reminders + adaptive UX + multimedia guidance + multilingual prompts + human concierge in 120+ languages when tech isn't enough |
| eConsent | Yes | Yes — multimedia with audit trail |
| Telehealth & video visits | Partner integration | Yes — built into platform |
| Compliance posture (HIPAA, GDPR, 21 CFR Part 11, ICH GCP, ISO 27001) | Yes | Yes |
| Engagement model | ||
| Pricing model | SaaS subscription + study setup | Outcomes-scoped integrated engagement |
| Accountability for outcomes | Customer's clinical operations team | Delve owns drift recovery between visits |
| Strongest fit | Academic, investigator-initiated, biotech-led EDC-first studies | Wearable-heavy, long-duration, or compliance-critical studies where completion is the deliverable |
Why outcomes-grade studies pick Delve over Castor
Four reasons sponsors pick Delve when patient compliance, wearable endpoint integrity, or retention are the deliverable — not the customer's problem to solve.
Completion guaranteed, not hoped for
Delve publishes documented 92–98% per-study eCOA/ePRO completion ranges as a platform deliverable. Castor EDC provides tools; the customer's clinical operations team owns the completion number. Different accountability models.
Your algorithm, not the device's
70+ validated digital-endpoint algorithms across ECG, glucose, activity, sleep, frequency, and QC — running on Delve's harmonized data layer, not consumer-grade vendor SDKs. Endpoint integrity is engineered, not assumed.
Humans recover patients. Period.
Patient drift gets recovered by trained humans in 120+ languages, not chatbots. AI agents handle internal paperwork well; they don't solve a caregiver in a rare-disease trial who's burned out, or a non-native speaker confused by an ePRO prompt.
Hourly readiness, not weekly reports
7-dimension compliance scoring updated every hour. Castor's EDC dashboards are designed to surface clean data; Delve's readiness scoring is designed to recover drifting patients before that data goes missing.
1. Human concierge vs. customer-driven recovery
Castor EDC delivers patient-facing support through its software platform plus (where needed) professional services or partners. Multilingual outreach, proactive compliance follow-up, and real-time recovery operations are typically handled by the sponsor's clinical operations team or contracted vendors.
Delve includes Concierge-as-a-Service as a built-in platform layer, with humans operating in 120+ languages, with documented response windows and escalation rules. The model targets the compliance loss that happens between visits — missed diaries, device confusion, wear-time decay — through trained humans, not chatbots.
Why it matters: in real-world studies, the majority of compliance loss does not show up in monitoring reports — it shows up in patient confusion, missed reminders, and device issues that need human follow-through. Whoever owns that follow-through determines completion rates.
2. Wearable platform depth
Castor EDC integrates with selected wearables and relies more heavily on vendor-supplied metrics. Delve runs 70+ validated digital-endpoint algorithms across 25+ supported devices on a harmonized clinical data layer that normalizes units, sampling rates, time bases, QC flags, and algorithm versions.
The data-layer engineering is the part most evaluators miss. Two vendors can both “support wearables” and have very different validation evidence behind the data each platform produces.
Why it matters: for wearable-heavy studies, endpoint integrity depends on more than just data ingestion. Validation evidence is part of the submission package.
Which platform fits your study
Choose the platform that fits your operating model
Both platforms run modern clinical trials successfully. The right answer depends on your study profile and your internal operating model.
Choose Castor EDC if…
- Your study is academic, investigator-initiated, or federally funded — Castor's Site License model and "For Impact" program are purpose-built for this
- Your bottleneck is study build speed and budget, not data continuity or wearable endpoint integrity
- Your endpoints don't depend on continuous wearable data and you don't need multilingual patient concierge
- You can self-manage compliance recovery internally without platform-owned outcomes
Choose Delve Health if…
- You're launching a multi-region study and need self-serve UI-driven tenant rollout (US/NA, EU, LATAM, APAC, MENA) without per-region procurement, IT tickets, or pre-built validated diary templates available on day one
- Your study is industry-sponsored — biotech, pharma, MedTech — where compliance and retention are commercial deliverables
- You need the same configurable eCOA / ePRO / eConsent Castor offers, plus a 70+ validated wearable algorithm library Castor doesn't have
- You need multilingual human concierge in 120+ languages as a platform layer, not a customer-managed service
- You want documented per-study completion (92–98%) and retention uplift (up to 63%) in your scope
- Your protocol is long-duration, wearable-heavy, or high-burden — rare disease, oncology, CNS, post-market
- You want platform-owned drift recovery between visits, not just a study-build tool
Frequently asked questions
Questions sponsors ask when comparing Castor EDC and Delve Health
These answers clarify the operational differences and how to evaluate them for your protocol.
How is Delve Health different from Castor EDC?
Castor is an open, configurable EDC platform with eCOA, ePRO, eConsent, and randomization modules — strong in academic and investigator-initiated research. Delve Health is a clinical trial compliance and retention operating system combining eCOA, ePRO, 70+ validated wearable endpoint algorithms, and human Concierge-as-a-Service in 120+ languages. The decision usually comes down to: do you need a flexible EDC core, or do you need a platform that owns compliance and retention outcomes?
Is Castor an eCOA vendor or an EDC vendor?
Castor's core is EDC. It offers eCOA / ePRO as modules on top of that EDC core. For pure eCOA-led studies — especially wearable-heavy, long-duration, or compliance-critical — sponsors often find that an eCOA platform built around compliance and retention (like Delve) is a better fit than an EDC platform with eCOA add-ons.
Does Castor include wearable algorithms?
Castor offers an open API for wearable, EHR, and lab integration but does not publish a proprietary validated algorithm library. The 2025 Castor Catalyst AI platform focuses on automating EDC workflows, not endpoint validation. Delve runs 70+ validated digital-endpoint algorithms across 25+ wearable devices on a harmonized clinical data layer. For endpoint-grade wearable studies, validation evidence matters more than integration count.
Does Castor include human patient support like Delve's concierge?
Castor's model is software-led; multilingual outreach, proactive compliance follow-up, and recovery operations are typically delivered by the sponsor's clinical operations team or a partner. Delve includes Concierge-as-a-Service in 120+ languages as a built-in platform layer with documented response windows.
Which platform is better for academic or investigator-initiated trials?
Castor was founded with academic and investigator-initiated research in mind, and remains strong for that segment. Delve is better positioned for industry-sponsored studies where wearable endpoint integrity, multilingual concierge support, and platform-owned completion outcomes are part of the deliverable.
When should I choose Castor over Delve Health?
Choose Castor when the priority is a fast, flexible, low-cost EDC core for an academic, investigator-initiated, or biotech-led study with moderate burden and straightforward eCOA needs. Choose Delve when the priority is documented per-study compliance and retention outcomes, multilingual human patient support, depth of validated wearable endpoints, and an operating model where the platform partner owns drift recovery between visits.
Related learning
Build a complete picture before you commit
Knowledge pages that help sponsors evaluating eCOA, DCT, and wearable platforms understand what separates execution-grade vendors from platforms that look good in demos.
How to choose an eCOA vendor
Evaluation criteria beyond software — execution, support, compliance, site impact.
Read the guide →eCOA Vendor Comparison framework
Dimensions that predict study performance — used to compare any pair of platforms.
Open the framework →Why eCOA data fails in real-world trials
Missed diaries, patient drift, fragmented systems — hidden failure modes and what fixes them.
Read more →How to measure compliance in clinical trials
A practical, vendor-neutral framework for measuring compliance across modalities.
Read more →Evaluating Delve against your current stack?
If you are comparing Castor EDC, Delve, or other DCT/eCOA platforms, ask each vendor one question: what happens when a participant stops responding? The answer tells you more than any demo.
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