" Why primary care needs to migrate to SNOMED CT Two versions of clinical codes (Read v2 and CTV3) currently exist in General Practice. Not all GP systems use the same coding system. Parts of the Read code vocabulary are full and new codes have been allocated to unrelated areas. This makes analysis more difficult. The NHS needs a single clinical terminology, for clinical data to be exchanged accurately and consistently across all care settings. This will allow better patient care and improve how clinical data can be analysed and reported on. SNOMED CT is an international clinical terminology. It will allow the UK to take part in more effective research and analysis of health information, to support national and global health care improvements." " When SNOMED CT is being implemented SNOMED CT will go live in general practice care in a phased approach from April 2018. The phased approach will: enable systems to preserve both SNOMED CT and Read Codes for a period of time to support the transition and implementation planning ensure national specifications that are provided in SNOMED CT can be supported while suppliers roll-out their solutions ensure that new clinical content for general practice that is released in SNOMED CT can be recorded and processed by all end users during the implementation The deployment rollout will commence with pilot sites for the four principal clinical system suppliers, EMIS, TPP, Vision and Microtest. This will commence from April 2018 with a phased roll-out approach ensuring year-end processes can be completed prior to implementation. " more here: https://digital.nhs.uk/SNOMED-CT-implementation-in-primary-care for background: https://www.snomed.org/snomed-ct/what-is-snomed-ct/history-of-snomed-ct see also for other countries: https://www.snomedinaction.org/ https://snomedbrowser.com/Codes/Details/52702003 note the Mild/Moderate/Severe CFS "This is a UK specific concept"