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Imperial College integration of Clinical Referral Information case study

Published - 10 July 2019 - This case study focuses on enabling effective referral management processes using Application Programming Interfaces (APIs) at Imperial College Healthcare.


Imperial College Healthcare recently partnered with the NHS e-Referral Service (e-RS) to maximise the full range of Paper Switch-Off benefits to reduce administrative costs and achieve quicker patient care through API integration of patient Clinical Referral Information (CRI).

The challenge

The project involved the design, development and implementation of a new integrated solution to allow Imperial to automatically access and import electronic first outpatient appointment CRI held within the e-RS solution into its internal Clinical Document Library and e-Vetting applications.

This activity has enabled Imperial to:

  • deliver more efficient management of over 150,000 GP referrals a year
  • clear a growing manual paper backlog
  • enhance clinical safety from reduced, incomplete or inappropriate referrals

National context

e-RS combines electronic booking with a choice of place, date and time for first hospital or clinic appointments. Patients can choose their initial hospital or clinic appointment, book it in the GP surgery at the point of referral, or later online or on the phone.

The NHS Standard Contract requires the full use of e-RS for all GP to consultant-led first outpatient appointments, with providers only being paid for activity resulting from referrals made through e-RS.

The term Application Programming Interface, or API, is used broadly to refer to any mechanisms which allow a system or service to access data or functionality provided by another system or service. The result is software interoperability.

The partnership

Imperial is a Trust with a workforce of 10,000, providing care for around a million people every year in their five hospitals and a growing number of community services in north west London. 

A partnership was established between Imperial’s ICT project and the e-RS programme’s Integration Portfolio Team to make the e-RS CRI or referral letter available within the e-RS application to Imperial’s internal applications, using agile software development and implementation techniques. 

The benefits of Clinical Document Integration using APIs


A more efficient clinical review process, ensuring appropriate referral decisions are made as soon as possible.


A reduced risk of clinical safety issues related to incomplete or inappropriate referrals.


Reductions in manual paper processing, data quality issues and overall clinical and administrative workload.


This project was the first nationally to achieve compliance and go-live with the newly released e-RS APIs.

Through close technical and implementation collaboration, the teams jointly created an outline prototype concept and established connectivity to the NHS Digital path-to-live test environments.

Supported by both virtual and onsite meetings, together with electronic collaboration tools, a working model of the proposed solution was rapidly generated for user review and feedback.

Once the outline design was approved, a new Target Operating Model (TOM) approach for product assurance was piloted leading to a successful launch on the 17 December 2018. 

This new approach to national system compliance is considered more appropriate, lighter-weight and significantly quicker than the preceding Common Assurance Approach (CAP), whilst not diminishing focus on pre-requisite information governance, clinical safety and service readiness preparations.

Solution design

The objective for the design was to remove the historical need for the trust’s staff to either login to e-RS to review the GP initiated referral or to manually prepare paper clinic notes for an offline, clinical review decision.

The goal was for the CRI to be transferred to the in-house Imperial Clinical Document Library (CDL) and e-Vetting applications, so that the information would be readily available to clinicians at point of need and thereby reduce the need for users to repeatedly switch between multiple software interfaces.

The diagram below shows how Imperial College Healthcare have integrated the e-RS Clinical Referral Information API with their existing systems to streamline their referrals management process.

The left half of the diagram shows the system retrieving the clinical referral information from e-RS and storing it in their local document management system, a process that was previously done manually. The right-hand side of the diagram shows that the next time the referral is accessed, the system uses the e-RS to check that the locally stored clinical referral information is still the latest available, if it is not then the updated information will be downloaded. The cross checking of local information with e-RS information was also performed manually, a step that has now been eliminated.


Imperial College Healthcare Trust e-referrals API integration

e-RS API case study image


PIMS is an in-house PMI (Patient Master Index) which is updated using Cerner messaging.
CDL (Clinical Document Library) is an in-house solution linked to Cerner EPR.
E-Vetting is an in-house solution to manage referrals from a range of sources.

Solution design by Imperial College Healthcare Trust, utilising the e-Referrals Service CRI API.


Imperial staff are now able to download the CRI with reduced manual intervention and are now working with e-RS implementation managers to evolve the solution to use new unattended (without the need for smartcards) API capabilities, as well as the next phase of the clinical review process, namely accept, reject or re-direct.

Benefits of the service

The NHS e-Referral Service has benefits for all users.

These include:

  • cost and time savings
  • fewer missed appointments
  • fewer inappropriate referrals
  • shorter referral to treatment times
  • choice of hospital or specialist
  • choice of appointment date and time

“This new API integration will immediately enable Imperial College Healthcare to re-deploy four administrative staff to front care.”

John Kelly - Head of Systems Solutions

Find out more about e-RS integration.

Last edited: 11 June 2020 2:49 pm