Inferensys

Glossary

Real-World Data Screening

The application of clinical trial matching algorithms to non-interventional data sources, such as EHRs and claims databases, to identify potential trial participants.
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DEFINITION

What is Real-World Data Screening?

Real-world data screening is the automated application of clinical trial matching algorithms to non-interventional data sources, such as electronic health records and claims databases, to identify potential trial participants outside of traditional site-based recruitment.

Real-World Data Screening is the computational process of analyzing routinely collected health data—including electronic health records (EHRs), insurance claims, and patient registries—to identify individuals who meet the complex inclusion and exclusion criteria of a clinical trial. Unlike traditional site-based recruitment, this method leverages existing, non-interventional data to proactively surface eligible candidates from broader, more diverse patient populations.

The core mechanism involves translating a trial's free-text eligibility criteria into computable phenotypes and executing them against structured and unstructured data within a real-world data repository. This requires robust temporal reasoning to validate time-dependent constraints and semantic normalization to map local clinical terminologies to standard ontologies, enabling a privacy-preserving pre-screening that accelerates cohort identification and improves site feasibility assessments.

REAL-WORLD DATA SCREENING

Key Characteristics of RWD Screening

Real-world data screening applies clinical trial matching algorithms to non-interventional data sources like EHRs and claims databases. The following characteristics define how these systems operate at scale.

01

Retrospective Cohort Identification

RWD screening operates on historical patient data rather than point-of-care encounters. The system analyzes longitudinal records—often spanning years—to identify patients who meet trial criteria at a specific moment in time.

  • Queries structured fields (ICD-10-CM, LOINC, RxNorm) and unstructured clinical notes simultaneously
  • Applies temporal reasoning to validate event sequences (e.g., diagnosis followed by progression within 6 months)
  • Generates a pre-screened cohort for feasibility analysis before site activation

Unlike prospective EHR-based screening, RWD approaches can assess population-level eligibility without interrupting clinical workflows.

Years
Typical Lookback Period
02

Multi-Source Data Harmonization

RWD screening ingests heterogeneous data from claims databases, EHR systems, and specialty registries, each with distinct schemas and coding conventions. The screening engine must normalize these sources into a unified patient model.

  • Maps proprietary lab codes to LOINC for cross-site comparability
  • Reconciles medication records from pharmacy claims with EHR prescription orders
  • Aligns diagnosis codes across ICD-9-CM and ICD-10-CM transitions
  • Handles duplicate and conflicting records through entity resolution

This harmonization layer is the prerequisite for applying consistent eligibility logic across disparate real-world datasets.

03

Unstructured Data Parsing at Scale

A defining characteristic of RWD screening is the ability to extract eligibility-relevant information from free-text clinical narratives that exist outside structured fields. Critical inclusion criteria—such as ECOG performance status or specific pathology findings—often reside only in notes.

  • Deploys medical named entity recognition to identify diseases, procedures, and measurements
  • Applies negation and uncertainty detection to distinguish affirmed findings from ruled-out conditions
  • Uses clinical entity linking to ground ambiguous mentions to standard ontologies (SNOMED CT, RxNorm)
  • Processes millions of documents across patient populations using distributed NLP pipelines

Without unstructured data parsing, RWD screening misses the majority of granular eligibility evidence.

04

Privacy-Preserving Architecture

RWD screening operates on sensitive patient data governed by HIPAA, GDPR, and contractual data use agreements. The screening architecture must enforce privacy controls while enabling computationally intensive analysis.

  • Executes screening algorithms within secure, audited environments rather than exporting raw data
  • Supports de-identified cohort reporting where only aggregate eligibility counts are exposed
  • Implements role-based access controls that limit which users can view patient-level results
  • Maintains comprehensive audit trails documenting every data access and screening execution

This privacy-by-design approach enables pharmaceutical sponsors to assess trial feasibility without assuming custody of protected health information.

05

Computable Phenotype Execution

RWD screening translates trial eligibility criteria into executable computable phenotypes—machine-processable definitions expressed as logical expressions over standardized data elements.

  • Decomposes complex criteria into atomic, evaluable components
  • Encodes temporal constraints (e.g., "no myocardial infarction within 90 days") as time-window predicates
  • Applies criteria weighting to prioritize patients based on the criticality of each requirement
  • Generates eligibility scores that rank patients by match quality rather than binary pass/fail

The phenotype execution engine applies these definitions across the harmonized data layer to produce ranked, auditable patient lists.

06

Feasibility-First Screening Paradigm

Unlike point-of-care screening that identifies individual patients during clinical encounters, RWD screening often serves a feasibility assessment function—answering "how many eligible patients exist in this population?" before sites are activated.

  • Produces aggregate eligibility counts stratified by site, geography, or demographic characteristics
  • Enables protocol optimization by revealing overly restrictive criteria that eliminate large patient segments
  • Supports site selection by ranking locations based on potential enrollment yield
  • Feeds recruitment timeline projections with data-driven enrollment rate estimates

This paradigm shift from reactive to proactive screening fundamentally changes how sponsors plan and execute clinical trials.

REAL-WORLD DATA SCREENING

Frequently Asked Questions

Clear, technical answers to the most common questions about applying clinical trial matching algorithms to non-interventional data sources like electronic health records and claims databases.

Real-world data (RWD) screening is the automated application of clinical trial matching algorithms to non-interventional data sources—primarily electronic health records (EHRs) and claims databases—to identify potential trial participants. Unlike traditional site-based recruitment, this process computationally evaluates patient profiles against a protocol's inclusion and exclusion criteria using data generated during routine clinical care. The core mechanism involves translating a trial's free-text eligibility requirements into a computable phenotype, which is then executed against a repository of structured and unstructured patient data. This approach enables the systematic, privacy-preserving identification of eligible cohorts directly from existing healthcare data infrastructure, bypassing the need for manual chart review as the primary recruitment driver.

Prasad Kumkar

About the author

Prasad Kumkar

CEO & MD, Inference Systems

Prasad Kumkar is the CEO & MD of Inference Systems and writes about AI systems architecture, LLM infrastructure, model serving, evaluation, and production deployment. Over 5+ years, he has worked across computer vision models, L5 autonomous vehicle systems, and LLM research, with a focus on taking complex AI ideas into real-world engineering systems.

His work and writing cover AI systems, large language models, AI agents, multimodal systems, autonomous systems, inference optimization, RAG, evaluation, and production AI engineering.