Patient Registry vs EHR: Differences, Similarities, Benefits

Mansha Kapoor
July 9, 2024

Health technology and its related IT has been evolving consistently and continuously since the past decade. Implementation of electronic health records (EHRs) is the widespread norm rather than an exception in hospitals and ambulatory care settings. The trend is further buttressed by the increasing use of applications (apps) and wearable devices. Individuals are able to generate large volumes of personal health data, for example, physical activity, heart rate, sugar levels and body temperature. Consequently, huge amounts of electronic health data are now available for use in retrospective and prospective research studies and quality improvement initiatives. Every day fresh efforts are being directed towards harnessing these data for clinical decision making, managing population health, and conducting proactive safety surveillance. 

The availability of electronic health data provides for patient registries to collect deep, nuanced data on large numbers of patients at significantly reduced costs. This is a considerable leap forward in comparison to manual collection of data using case report forms. A patient registry is defined as an organized system that uses observational study methods to collect uniform data (clinical and other) to evaluate specified outcomes for a population defined by a particular disease, condition, or exposure and that serves one or more pre-determined scientific, clinical, or policy purposes.

An electronic health record (EHR) is a digitalized record of patient’s paper chart. EHRs are real-time, patient health records that give information instantantaneously and securely to authorized users. An EHR contains a patient’s medical history, diagnoses, medications, treatment plans, immunization dates, allergies, radiology images, and laboratory and test results. While both patient registries and EHRs might sound similar and interchangeable; they have hairline differences that serve different purposes and processes. However, both contribute to promoting the concept of learning health systems. 

Use of EHRs & Patient Registry in the Healthcare

There is a strong advocacy for learning health system. AHRQ (Agency for Healthcare Research and Quality) defines a learning health system (LHS) as a health system in which internal data and experience are systematically integrated with external evidence, and that knowledge is put into practice. A robust implementation of LHS is inevitably dependent on the availability of Real Word Data. The LHS, thus designed will be able to provide the best collaborative healthcare choices for patients and provider. However, what is RWD based on?

EHR and patient registries become the source for RWD. EHR data is heterogeneous, structured, and unstructured (e.g., text, imaging). EHRs provide humungous opportunities for data-driven approaches to learn patterns, make new discoveries, assist preoperative planning, diagnostics, clinical prognostication. EHRs are also utilized to improve predictions particularly when studied in tandem with administrative and claim data. The success rate gets further enhanced when machine learning techniques are applied to validate and replicate findings from clinical trials.

Patient registries are an organized way of collecting RWD using observational methods and following the same patients over time. They may be organized as either disease or product (treatment) registries. Registries enroll patients notwithstanding the treatment status for the purpose of characterizing the natural history of the disease (which is often limited in rare disease), the effectiveness and real-world safety of different treatments. 

Patient registries have a major role to play in improving healthcare delivery which is largely dependent on the use of healthcare analytics. Analysis of data and statistical progress from patient registries help researchers identify gaps in care, areas for improvement, and potential risk factors for rare diseases. Registries provide a data source for decoding the course of a disease, and providing critical information for a clinical trial design. They become particularly important for rare diseases where clinical trials are often of small size and data are subject to high variability. 

Briefly EHRs streamline workflows, reduce errors, and enhance the quality of care. On the other hand, Patient Registries aggregate data for groups of patients who share common conditions or treatments, enabling robust research and public health initiatives. These registries are the backbone of evidence-based medicine, driving improvements in treatment protocols and patient outcomes.

What is a Patient Registry?

"A patient registry is an organized system that uses observational study methods to collect uniform data (clinical and other) to evaluate specified outcomes for a population defined by a particular disease, condition, or exposure and that serves predetermined scientific, clinical, or policy purpose(s)” as found in National Centre for Biotechnology Information.

Simply put a patient registry is a collection of complete information about individuals, with a specific diagnosis or with specific risk factors for a disease. The information would include medical history, diagnosis, treatments, reactions and responses. These registries become the basis of clinical trials and research studies. Therefore, clinical research trials and studies that are based on a well-designed and well-performed patient registries are powered to provide a real-world view of clinical practice, patient outcomes, safety, clinical, comparative, and cost-effectiveness. They also serve to feed a number of evidence development and decision making purposes. Think of a Patient Registry as a specialized library, meticulously curated to house detailed information about patients with specific conditions. 

Uses of Patient Registry

Patient Registries have a multitude of uses, some of the most common ones are;

1. Research and Clinical Trials:

They provide rich datasets for researchers, helping identify trends, treatment outcomes, and potential areas for new studies.

2. Quality Improvement:

Healthcare providers use registry data to evaluate and enhance the quality of care, identifying gaps and implementing best practices.

3. Public Health Monitoring:

Registries support public health agencies in tracking disease outbreaks, vaccination rates, and other crucial health metrics.

4. Patient Care:

By collecting detailed information about patient outcomes, registries help clinicians tailor treatments and monitor long-term health trends.

What are EHRs?

Electronic Health Records (EHRs) are the digital equivalent of a patient's paper medical chart. However, they offer much more than just a static repository of information. EHRs integrate with various healthcare systems, providing a dynamic, real-time view of patient health.

EHRs are invaluable for several reasons:

- Comprehensive Patient Histories: EHRs compile all patient interactions, lab results, medications, and treatment plans into a single, easily accessible record.

- Coordination of Care: By enabling seamless information sharing among healthcare providers, EHRs ensure that every member of a patient's care team is on the same page.

- Efficiency: EHRs reduce administrative burdens, minimize errors, and streamline processes like billing and appointment scheduling.

- Patient Engagement: Many EHR systems offer patient portals, empowering individuals to take an active role in managing their health.

EHRs vs. Patient Registries: Differences, Similarities, and When to Use

EHRs and registries work to harvest clinical information at the patient level. EHRs are used for assistance in certain functions that a patient registry requires (e.g., data collection, data cleaning, data storage). A registry uses the information collected in an EHR (e.g., population views, quality reporting) for various healthcare delivery related decisions.  In practice, there may be some overlapping functionality between EHRs and registries, but their roles are distinct. The only similarity lies in their importance to the health care system. 

EHR and a registry are not to be confused with each other. Both EHRs and Patient Registries manage patient data. But they do so in fundamentally different ways. It is their distinct roles that sets them apart.  Registries are population focused, purpose driven, and designed to derive and analyze information on health outcomes. EHRs are focused on the collection and use of an individual patient's health-related information. Here’s a closer look at their differences, similarities:


- Scope of Data: EHRs are patient-centric, containing detailed records of individual patients’ medical histories. In contrast, Patient Registries are disease or condition-centric, focusing on cohorts of patients.

- Purpose: EHRs are designed for daily clinical use, helping providers deliver personalized care. Patient Registries are research-oriented, used to analyze trends and outcomes across groups of patients.

- Data Collection: EHR data is gathered in real-time during patient visits, while patient registry data is often collected longitudinally, sometimes from multiple sources, to track long-term outcomes and trends.


- Digital Records: Both systems digitize patient information, moving away from paper-based records.

- Data Analysis: Both EHRs and Patient Registries support data analysis to improve patient outcomes, though the scale and focus of the analysis differ.

- Improving Care: Ultimately, both tools aim to enhance the quality and efficiency of healthcare delivery.

When to Use:


Use EHRs for day-to-day patient management, ensuring that every healthcare provider involved in a patient's care has access to the most current and comprehensive information. EHRs are essential for immediate clinical decision-making and continuity of care. Access to EHRs allows patients to view past clinical notes, look at lab test results and medications at a flick of a finger, use the messaging system to get in touch with their healthcare providers, and check bills of clinical visits, instantaneously. The implementation of EHRs is worthwhile for both healthcare institutions and individual patients. EHRs greatly help healthcare institutions in trimming medical costs, tracking patient data any time and over a period of time, and improve healthcare delivery quality. Secondly, easy access to their medical records educates and empowers patients to understand their medical history and health condition. Prior knowledge saves time and cost, increases their choice making from amongst the Medicare available and reduces the inconvenience of travel for medical and administrative purposes.

- Patient Registries:

Employ Patient Registries when conducting research, monitoring public health, or implementing large-scale quality improvement initiatives. Registries are ideal for understanding disease patterns, evaluating long-term outcomes, and informing clinical guidelines. A patient registry is a repository of information about the course of disease referenced on collected EHRs. It is employed for the following functions:

1. Observe the course of disease; 

2. Understand variations in treatment and outcomes; 

3. Examine factors that influence prognosis and quality of life; 

4. Describe care patterns, including appropriateness of care and disparities in the delivery of care; 

5. Assess effectiveness; 

6. Monitor safety and harm; 

7. Measure quality of care. 

Different stakeholders derive different value from registries. For example, for a clinician, registries can produce a real-world picture of disease, current treatment practices, and outcomes. 

For a physician organization, a patient registry platform has data that can be used to calibrate the degree of presence of a disease in accordance with evidence-based guidelines. Registries can help them focus attention on specific aspects of a particular disease that could be missed otherwise. 

From a payer's perspective, registries provide detailed information on how procedures, devices, or pharmaceuticals are actually used and their effectiveness amongst different populations. This information is vital for determining health insurance coverage policies. 

For a drug or device manufacturer, a registry-based study will guide him in determining the performance of a product in the real world. Armed with this knowledge he can meet a post-marketing commitment or requirement, develop hypotheses, or identify patient populations that will be ideal for his product development, clinical trials design, and patient recruitment. 


In the world of healthcare, where precision and efficiency are paramount, both EHRs and Patient Registries play crucial roles. EHRs provide a detailed, real-time snapshot of individual patient health, essential for immediate care and coordination among providers. Patient Registries, with their focus on specific conditions and long-term outcomes, are invaluable for research, public health, and quality improvement.

Understanding the differences and complementary strengths of these systems allows healthcare providers to harness the full potential of digital health tools. By leveraging EHRs and Patient Registries appropriately, we can move closer to a future where healthcare is not only more efficient and coordinated but also more personalized and effective. And in that future, every patient’s story is a data point driving better health for all. But this can only happen when there is issueless EHR-Patient Registry interoperability. The EHR is moving towards becoming primary desktop interface for physicians and clinicians and health workers. Registries might have to work through EHRs to make interoperability feasible and EHRs might have to be an interface for more than one registry, simultaneously.

"In a truly interoperable system, registry-specific functionality could be presented in a software-as-a-service or middleware model, interacting with the EHR as the presentation layer on one end and the registry database on the other. In this model, the EHR is a gateway to multiple registries and clinical research activities through an open architecture that leverages best-in-class functionality and connectivity. Registries interact across multiple EHRs, and EHRs interact with multiple registries” as per the National Centre for Biotechnology Information.

Mahalo Health's digital healthcare platform accelerates healthcare breakthrough in weeks. It’s bandwidth gives your patient population and research team the user experience they desire and expect. Mahalo facilitates you in easy sharing of ePRO questionnaires and lets patients import medical records, labs, and biomarker data from 260+ connected devices. With Mahalo patients can self-register and complete surveys from any device. Amongst its other virtues are: automating EHR data retrieval, storing large files in a unified system, streamlining the eConsent process, and migrating seamlessly from your existing registry with expert support. The platform enhances patient education with micro-learning content and engages them with personalized notifications. Above all the platform ensures ISO, HIPAA, and GDPR compliance.

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