Claims vs. EHR Data
Claims vs. EHR Data: Strengths, Limitations, and Use Cases
Real‑world evidence (RWE) is only as strong as the data behind it. And in today’s landscape, two sources dominate: administrative claims and electronic health records (EHRs). Both are powerful. Both are imperfect. And both can lead to misleading conclusions when used for the wrong research question.
The most effective HEOR and RWE teams don’t treat claims and EHR data as interchangeable. They treat them as complementary tools, each suited to specific decisions, endpoints, and payer needs.
Below is a clear, strategic breakdown of how to use each source to generate evidence that is credible, clinically meaningful, and payer‑relevant.
Claims Data: Strengths, Limitations, and Best‑Fit Use Case
Strengths
Claims data is the workhorse of RWE and for good reason. It offers:
Large, diverse, and geographically broad populations
Complete visibility into billed services, including pharmacy, outpatient, inpatient, and procedures
Longitudinal follow‑up as long as patients remain enrolled
Reliable cost and utilization data
Standardized coding (ICD‑10, CPT, HCPCS, NDC), enabling reproducible cohort definitions
These strengths make claims data ideal for understanding how care is delivered and paid for in the real world.
Limitations
But claims data has blind spots:
No clinical detail (labs, vitals, staging, biomarkers)
Limited insight into disease severity
No direct measures of clinical response or progression
Potential misclassification due to coding variability
Gaps in enrollment that can break longitudinal follow‑up
Claims data tells you what happened, not why it happened.
Best‑Fit Use Cases
Claims data excels when the research question involves:
Treatment patterns and sequencing
Adherence, persistence, and discontinuation
Health care resource utilization (HCRU)
Total cost of care and budget impact
Safety signals are detectable through diagnoses or procedures
Large‑scale epidemiology (incidence, prevalence)
Quality measure performance (HEDIS, PQA)
If the endpoint is economic, utilization‑based, or population‑level, claims are usually the right starting point.
EHR Data: Strengths, Limitations, and Best‑Fit Use Cases
Strengths
EHR data brings the clinical richness that claims lacks:
Lab values, vitals, imaging results, and biomarkers
Disease severity, staging, and line of therapy
Clinical outcomes and response proxies
Provider notes and unstructured text (when available)
Medication orders, not just fills
More granular timing of clinical events
EHRs reveal the clinical context behind treatment decisions.
Limitations
But EHR data also comes with challenges:
Fragmentation across health systems
Missingness and inconsistent documentation
Limited visibility into care outside the system
Variable coding practices
Shorter follow‑up compared to claims
Limited cost data
EHRs are clinically rich but operationally messy.
Best‑Fit Use Cases
EHR data is ideal for:
Clinical severity and baseline risk adjustment
Biomarker‑defined subgroups
Real‑world response or progression proxies
Line‑of‑therapy identification
Safety outcomes requiring labs or vitals
Comparative effectiveness with clinically relevant endpoints
Rare disease phenotyping
If the endpoint requires clinical nuance, EHRs are indispensable.
When to Use Linked Claims + EHR Data
The most compelling RWE often comes from linked datasets, which combine the scale of claims with the clinical depth of EHRs.
Linked data is especially powerful for:
Comparative effectiveness with robust confounding control
Cost‑effectiveness and budget impact modeling
Real‑world progression‑free survival (rwPFS)
Treatment sequencing informed by both clinical and economic factors
Safety outcomes requiring both labs and utilization
Value‑based contract monitoring
When payers want a full picture (clinical, economic, and behavioral), linked data delivers.
How Payers Interpret Claims vs. EHR Evidence
Payers increasingly understand the strengths and limitations of each source. In practice:
Claims‑based studies are trusted for cost, utilization, adherence, and population‑level patterns
EHR‑based studies are trusted for clinical nuance, severity adjustment, and subgroup insights
Linked studies are viewed as the gold standard when evaluating real‑world effectiveness and value
The key is transparency: clearly articulate why the chosen data source is fit‑for‑purpose and how limitations were addressed
The Bottom Line
Claims and EHR data are not competitors; they are complementary assets. The strongest RWE strategies use each source intentionally, aligning the data to the decision, the endpoint, and the payer’s evidence needs.
When used thoughtfully:
Claims data reveals patterns, costs, and utilization
EHR data reveals clinical nuance and patient complexity
Linked data reveals the full story of real‑world care
The result is evidence that is not only scientifically credible but strategically influential.
Let’s Keep the Conversation Going
If you’re navigating how to choose the right data source or how to design studies that resonate with payers, I’d love to hear what questions you’re exploring and what challenges you’re facing in your RWE strategy.

