Written by Technical Team | Last updated 31.07.2025 | 5 minute read
As the NHS continues its digital transformation journey, the ability to integrate healthcare systems securely and efficiently has never been more critical. System C’s CareFlow Electronic Patient Record (EPR) is at the heart of many Trusts’ clinical operations, ensuring patient data flows seamlessly across services. However, with interoperability comes the challenge of maintaining data consistency and integrity. For digital health innovators developing solutions that integrate with System C, understanding how to safeguard these principles is essential for delivering safe, reliable and future‑proof digital health technologies.
Data consistency refers to ensuring that information across multiple systems is always accurate, up‑to‑date and reliable. In a healthcare setting, where decisions are made in real time and patient safety is paramount, even minor inconsistencies can have serious consequences. An updated address, a corrected diagnosis, or a changed treatment plan must be reflected across every connected system to avoid clinical risks and administrative inefficiencies. When integrating with CareFlow, innovators must ensure their solutions handle patient identifiers, demographic updates, admissions, referrals and results in a way that maintains complete alignment with the CareFlow EPR.
System C has designed CareFlow and its CareFlow Integration Engine (CIE) to preserve integrity throughout the messaging process. Messages are transmitted via the HL7 protocol using the Minimal Lower Layer Protocol (MLLP) over TCP/IP. Each message is stored in a queue and delivered in a First‑In‑First‑Out sequence, ensuring strict ordering. Importantly, messages are only removed from the queue once an acknowledgement (ACK) is received from the receiving Trust Integration Engine (TIE), guaranteeing no data is lost in transit. This approach provides a robust foundation for innovators seeking to build upon CareFlow’s infrastructure.
A significant challenge for digital health innovators is the management of patient identifiers. CareFlow uses a Master Patient Index (MPI) to ensure that each patient has a single, unique identity across all systems. Inbound messages should include both the local hospital identifier and the verified NHS number, ensuring accurate linkage to the correct patient record. HL7’s conventions for handling null and empty fields allow innovators to manage changes correctly without overwriting essential data. For instance, omitting an optional field retains the existing value, whereas sending a null explicitly clears the field. Understanding and applying these rules is critical to maintaining consistency in patient records.
The flow of inpatient data is central to CareFlow integration. Admission, Discharge and Transfer (ADT) messages such as ADT^A01, ADT^A02 and ADT^A03 keep patient location and status information synchronised. Consistency in these messages ensures that when a patient is admitted, transferred or discharged, every connected system reflects the same status. For innovators creating applications that interact with clinical workflows, ensuring these messages are correctly received and processed is vital for maintaining accurate care pathways.
Outpatient and referral management also depends on reliable data flows. Messages such as REF^I12 for patient referrals and ADT^A05 for pre‑admissions must be correctly mapped and processed. Any inconsistencies in these workflows could result in missed appointments, duplicate bookings or delayed care. For innovators, rigorous testing and validation of referral and appointment messages within the CareFlow ecosystem ensures that patients receive the right care at the right time without administrative errors.
CareFlow supports diagnostic and laboratory processes through order and result messaging. Orders are managed using OMG^O19 or OML^O33 messages, while results are communicated via ORU^R01 or OUL^R22. Maintaining integrity in these workflows is essential to ensure that clinicians have immediate and accurate access to test results. Errors or inconsistencies here could directly affect patient treatment. Digital health innovators must ensure that their integrations preserve the order‑result linkage and handle result updates, amendments and verifications in alignment with CareFlow’s HL7 messaging standards.
Integrating with System C is not without its challenges. One of the most common is the risk of duplicate or mismatched records, particularly when patient identifiers are not correctly managed. Timing issues, where messages are delayed or processed out of sequence, can also threaten data integrity. Innovators must therefore design their systems to handle retries, acknowledgements and exception handling gracefully. System C’s approach of queuing and guaranteed delivery helps mitigate these risks, but integration partners must ensure their solutions are configured to take full advantage of these safeguards.
Thorough testing is a cornerstone of ensuring data consistency during integration. From initial interface planning through to live deployment, innovators should validate every message type and workflow, using both expected and edge case scenarios. This includes checking that null versus empty field handling is correctly applied, ensuring duplicate records are avoided, and verifying that acknowledgements are consistently returned. Partnering with experienced integration specialists can accelerate this process and reduce the risk of errors during rollout.
Beyond safety and compliance, maintaining data consistency and integrity during System C integration provides strategic benefits. Reliable integration enhances trust between clinicians and digital tools, drives adoption of new technologies, and supports the delivery of more efficient, joined‑up care. For digital health innovators, a track record of consistent, accurate integration with CareFlow can also provide a competitive advantage when working with NHS Trusts and other healthcare providers.
System C’s CareFlow EPR provides a powerful foundation for digital healthcare innovation, but its value is maximised only when integrations maintain the highest standards of data consistency and integrity. For digital health innovators, understanding the principles of HL7 messaging, the role of the CareFlow Integration Engine, and the nuances of patient identifiers and clinical workflows is essential. By approaching integration with rigour, leveraging System C’s robust safeguards, and prioritising thorough testing, innovators can ensure their solutions support safe, accurate and transformative healthcare delivery across the NHS.
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