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What are the main EHR limitations, and why can't your EHR answer clinical questions?
Your EHR was built to keep the legal record, place orders, and support billing, and it does those well. Its main limitation for clinical reasoning is that outside data often arrives as documents, not data. A scanned lab report is an image, so the EHR can't search it, trend it, or compare it with your own results.
By the end of 2025, 464 million documents had been exchanged through TEFCA, the federal "network of networks" for health information, ASTP/ONC reported in February 2026. More than 71,000 sites now take part.
Exchange is growing. Use is a different question. In 2021, the most recent year in ONC's physician quick stats, 53% of office-based physicians received patient information electronically, but only 38% integrated outside information into their EHR.
That gap is where clinical questions go unanswered. This page explains what the EHR was designed for, why outside results don't trend, why records still don't move freely between practices, and what can sit beside the EHR without replacing it.
What was the EHR built to do?
The EHR was built to store the patient record, manage orders, and support billing and reporting. Federal incentives shaped how EHRs spread. The HITECH Act created the Medicare and Medicaid EHR Incentive Programs, and by early 2014 more than 335,000 professionals had received payments for adopting certified EHRs or demonstrating meaningful use, according to ONC.
Adoption is now nearly universal. In 2024, 95.0% of office-based physicians used an EHR, according to the CDC's National Center for Health Statistics.
The time studies show where EHR work goes. In a study of 142 family physicians, Arndt and colleagues found physicians spent 5.9 hours of an 11.4-hour day in the EHR. Order entry, billing and coding, and system security took 2.6 hours, nearly half of that EHR time.
What is the EHR good at?
It is good at the data it creates itself. Results from a lab interfaced to your EHR, your medication list, your problem list, and your orders are usually stored as structured data. You can list, search, and often graph those.
The trouble starts with everything that arrives from outside.
What are the main EHR limitations for clinical reasoning?
The EHR stores information well and connects it poorly. Four limitations matter most in a cash-pay practice:
- It stores documents, not always data. A faxed or scanned report is an image of a page, not a set of values.
- It files outside records separately. Receiving a record is not the same as integrating it, and in 2021 only 38% of office-based physicians integrated outside information, according to ONC.
- It sends more than a clinician can review. In a VA survey published in 2013, Singh and colleagues found practitioners received a median of 63 notifications a day. Of them, 69.6% said they got more than they could manage, and 29.8% said they had missed abnormal results that delayed care.
- It shows what is in the chart, not what is missing. An EHR won't usually tell you that the last three thyroid panels came from three labs, or that a baseline was never drawn.
A 2024 narrative review in JMIR Medical Informatics, by Asgari and colleagues, linked these design problems to clinicians' cognitive load. It noted that working memory "can keep 3 to 5 items in mind at a time."
Why can't you search your EHR for a specific lab value?
Because a scanned value isn't stored as a value. When an outside report is scanned in, the EHR holds a picture of the page. Search can find structured results and typed text, but it can't read a number inside an image unless someone or something extracts it.
That extraction is harder than it looks. Ma and colleagues, writing in BMC Medical Informatics and Decision Making in 2023, described manual re-entry of paper lab reports as "time-consuming, labor-intensive and costly." Their automated system reached an overall F1 score of 0.86 on 153 reports. That is good, but not perfect, so someone still has to check the output.
Why don't outside lab results trend in your EHR?
An EHR can only draw a trend line through results it knows are the same test, in the same unit. Outside results often arrive without that information in a form the EHR can read.
What does a lab result need before it can trend?
Three things, in structured form:
- A standard test code. LOINC (Logical Observation Identifiers Names and Codes) is "a clinical terminology important for laboratory test orders and results," as the National Library of Medicine describes it.
- A standard unit. The HL7 US Core laboratory result profile says "a LOINC SHALL be used if the concept is present in LOINC," and that numeric units "SHALL be selected from UCUM," the Unified Code for Units of Measure.
- A reference range. The same profile lists the result reference range as a must-support element.
A result that arrives with all three can sit on the same graph as your own. A PDF has none of them in a form the EHR can use.
How do you compare results from two labs with different units and ranges?
Carefully, and with the source of each result written down. There are three separate problems:
- Units differ. Mayo Clinic Laboratories reports total testosterone in ng/dL and lists a factor of 0.0347 to convert it to the SI unit, nmol/L. A trend line that mixes the two without converting is wrong.
- Reference ranges differ. Each laboratory "establishes or 'validates' its own reference ranges," because of differences in equipment, reagents, methods, and reference populations, as Testing.com explains.
- Methods differ. CDC runs a Hormone Standardization Program for testosterone and estradiol. It certifies a testosterone assay only if its mean bias is within ±6.4% of CDC's reference values. CDC notes in its program overview that the Endocrine Society has described the need to improve the accuracy of these tests through standardization.
Scriptura's suggestion for any trend that crosses labs:
- Record the lab, the date, the unit, and the reference range next to each value.
- Convert units before you compare, and note that you converted.
- Read each result against its own lab's range.
- Treat a change that coincides with a change of lab as uncertain until you can repeat it at the same lab.
What kind of tool can sit beside your EHR?
Decision support software that reads across your chart, outside records, labs, and device data, and prepares a summary or recommendation for you to review. It works beside the EHR. It does not replace it.
Two open HL7 standards let such tools connect to an EHR when the EHR supports them:
- SMART App Launch "authorizes a user-facing client application ("App") to connect to a FHIR Server," often from inside the user's EHR session.
- CDS Hooks is a pattern "for invoking decision support from within a clinician's workflow," at moments such as opening a chart.
Whatever tool you use, test it against the fourth of FDA's criteria for decision support software that isn't a medical device. The software must let the clinician independently review the basis for its recommendations, as Covington's summary of FDA's January 2026 guidance sets out. If you can't see which lab, note, or guideline a recommendation came from, you can't check it.
What should stay in the EHR, and what can move beside it?
The record stays in the EHR. The reasoning across sources can happen beside it. This split is Scriptura's suggestion:
| Job | Where it belongs |
|---|---|
| Signed notes, orders, prescriptions, consent | EHR |
| Billing, coding, and quality reporting | EHR |
| Results from your interfaced lab | EHR |
| Combining outside labs from several labs into one trend | Beside the EHR, then summarized in the note |
| Reconciling units and reference ranges | Beside the EHR, with the method recorded |
| Reviewing wearable trends | Beside the EHR, with a summary in the note |
| The final plan and your reasoning | EHR |
If it informed a decision, a summary of it belongs in the signed note.
What is already on record, and what should you watch?
On record as of October 30, 2026:
- In 2024, 95.0% of office-based physicians used an EHR (CDC).
- In 2021, 38% of office-based physicians integrated outside information into their EHR, and 16% engaged in all four interoperability domains (ONC).
- By the end of 2025, 464 million documents had been exchanged through TEFCA, which had 11 QHINs as of February 2026 (ASTP/ONC).
- US Core requires LOINC for lab tests where a code exists and UCUM for numeric units.
- Information blocking rules under the Cures Act apply to providers, certified health IT developers, and HIEs and HINs.
Watch:
- New ONC data on physician interoperability more recent than 2021.
- Growth in TEFCA participation, and whether your EHR vendor joins a QHIN.
- Information blocking rulemaking. ASTP/ONC did not finalize its proposed changes in the HTI-5 rule, Reed Smith reported, and may return to them later.
- Whether the labs you use send structured results with LOINC codes or PDFs.
Frequently asked questions
What are the main EHR limitations?
For clinical reasoning: outside records stored as images, limited integration of outside data, more notifications than clinicians can review, and no view of what is missing.
Why can't I trend outside lab results in my EHR?
The EHR can only trend results it recognizes as the same test in the same unit. Scanned reports have no structured code, unit, or range it can read.
Why can't I search my EHR for a specific lab value?
A scanned report is a picture of a page. Search finds structured data and typed text, not numbers inside an image.
What is LOINC?
A standard code set for naming laboratory tests, produced by the Regenstrief Institute. It lets two systems agree that two results are the same test.
Can I compare testosterone results from two different labs?
With care. Convert to the same unit, read each result against its own lab's reference range, and treat changes that coincide with a change of lab as uncertain.
Why don't EHRs from different practices share records automatically?
Exchange depends on networks, vendor participation, and agreements. Many records still move by fax or PDF.
Is a practice allowed to refuse to share records?
Information blocking rules under the Cures Act restrict practices that are likely to interfere with access to electronic health information, subject to exceptions. Patients also have a HIPAA right to access their own records.
Do I need a new EHR to fix this?
Usually not. A tool beside the EHR can combine outside data, and the signed plan stays in the EHR.
What is TEFCA?
A nationwide "network of networks" for health information exchange, led by ASTP/ONC, with 11 QHINs as of February 2026.
What should go into the note when I use outside data?
A summary of the data that informed your decision, its source and date, and your reasoning.
About the author
How can Scriptura help when your EHR can't trend outside data?
If your patients' outside labs, records, and device data sit in your EHR as separate documents, book a demo to see how Scriptura's clinical decision support brings them into one view, with each source shown, for you to review and sign. Clinicians verify their license before platform access.
Educational and regulatory information only
This article is educational content only. It is not medical or legal advice and does not create an attorney-client or clinician-patient relationship. Privacy rules depend on your clinic's status and state. Confirm your obligations with a healthcare attorney licensed in your state before acting.
