Health call INR monitoring project by County Durham and Darlington Foundation Trust, Roche and Inhealthcare


County Durham and Darlington NHS Foundation Trust (CDDFT), Roche and Inhealthcare collaboratively created and piloted a self-testing service for patients who take warfarin, allowing them to be monitored outside the clinic. Patients used a self-testing device created by Roche to test their International Normalised Ratio (INR) levels and sent their results to the warfarin clinic through Inhealthcare’s automated platform. The entire project was overseen by staff at the CDDFT warfarin clinic, who contributed in the creation of its digital pathway. The project reduced the time patients spent attending the warfarin clinic and demonstrated significant lifestyle improvements. Meanwhile, there was an increase in the time patients were within their therapeutic range. CDDFT evaluations of service found it to be replicable and financially sustainable and, based on this, the Trust subsequently established a Health Call Monitoring service, in conjunction with Inhealthcare, as a permanent patient service. 


An estimated 1 million people in the UK take warfarin, mostly to reduce the risk of potentially serious conditions such as deep vein thrombosis, pulmonary embolism, heart attack and stroke. Its use requires careful monitoring, with patients having to attend the clinic at least monthly, and sometimes as frequently as weekly, for a blood test by a healthcare professional, in order to measure how quickly their blood is clotting and whether their dosage needs to be adjusted. As a result, the disruption to patients’ lives is great – in terms of time, money and inconvenience - so it would be desirable to use digital healthcare to allow patients to monitor their conditions and warfarin dosage without regular trips to the clinic.


They were three-fold:

  • To reduce the time patients spent in the clinic, thereby lessening work disruption, money spent travelling to the clinic and increasing the ability to travel while taking warfarin – all the while maintaining patients’ feeling that they were being monitored safely, and that the warfarin clinic staff were still accessible if they were needed. 
  • To improve the service of the warfarin clinic, making the process of monitoring conditions simpler and easier for both patients and staff. 
  • Improving patient outcomes, assessing what percentage of the time patients were within the therapeutic range (TTR) – i.e. taking the correct dosage – while on the trial, in comparison to the percentage of patients who were within TTR beforehand.

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Mr Ian Dove

Job title:
Business Development Manager
Place of work:
County Durham and Darlington Foundation Trust, Darlington Memorial Hospital
07500 127348