SystmOne is a centrally hosted clinical computer system developed by Horsforth-based TPP (The Phoenix Partnership). It is used by healthcare professionals in the UK predominantly in Primary Care. The system is being deployed as one of the accredited systems in the government's programme of modernising IT in the NHS.
SystmOne is one of the computer systems available to GPs under the  scheme from 2008, as well as through Local Service Provider, the CSC Alliance. Like other GP systems it makes extensive use of Read codes. Like most other GP systems all data is held on remote servers. It can be accessed using a mobile phone. It is widely used in TPP's home county of Yorkshire and is the system supporting the Born in Bradford project. EMIS Web (by Egton Medical Information Systems) is a rival clinical system which is more widely used across England as a whole.
The system is used to connect all prisons in England to a single clinical IT system for healthcare across the 133 prisons and young offender institutions and three immigration centres. The prison system does not communicate with the systems used by the NHS.
SystmOne is available as a number of different modules designed for different care settings. Modules for GP, prisons, child health, community units and palliative care are currently widely used throughout the NHS. In 2013, a number of secondary care modules were rolled out. These include modules for community and acute hospitals, accident and emergency, maternity, mental health and social services. TPP are involved in the development of electronic patient record systems converting large numbers of paper records into digital form. This enables GPs, community services and care homes to share access to records, with the patient's consent, enabling the ordering of clinical tests and medication without the need to visit the institution. Visiting clinical staff can use IT equipment in the institution to access patient records.
It is possible to use the system to send automated text messages to patients such as reminders for influenza vaccine.
The company has a close relationship with researchers at the University of Leeds with whom they developed an electronic frailty index. The company has a database with 6 million de-identified patient records, called ResearchOne, which in 2015 supported 40-50 research projects. About half have the potential to inform new clinical decision support tools. One is the Screening Tool of Older People's potentially inappropriate Prescriptions (STOPP) developed in Newton Abbott. This is intended to alert prescribers to risky combinations of medication. SystmOne permits rapid sharing of such applications.
SystmOne supports Summary Care Records. In March 2015 the company made an agreement to share patient data with Egton Medical Information Systems the biggest supplier of GP software after IMS MAXIMS released an open source version of its software, which acute trusts can use and alter the code to tailor the system to their needs. The companies say they hope to deliver functionality to support cross-organisational working such as shared tasks and shared appointment booking. This agreement is independent of the medical interoperability gateway. 
In October 2015 it was reported that the company was working with Central London Community Healthcare NHS Trust and Waltham Forest Clinical Commissioning Group on two pilots that will allow users of its software to see patient records on EMISweb and vice versa without any external software.
Potential risk to patient medical records
On 21 March 2017 the Information Commissioner's Office (Manchester UK) issued a statement regarding the data sharing capabilities of Systm One
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