Read codes are a clinical terminology system that was in widespread use in General Practice in the United Kingdom until around 2018, when NHS England switched to using SNOMED CT. Read codes are still in use in Scotland and in England were permitted for use in NHS secondary care settings, such as dentistry and mental health care until 31 March 2020.
Read codes support detailed clinical encoding of multiple patient phenomena including: occupation; social circumstances; ethnicity and religion; clinical signs, symptoms and observations; laboratory tests and results; diagnoses; diagnostic, therapeutic or surgical procedures performed; and a variety of administrative items (e.g. whether a screening recall has been sent and by what communication modality, or whether an item of service fee has been claimed).
In 1988 a joint conference of the Royal College of General Practitioners and the British Medical Association recommended standardisation of the system in general practice Electronic Medical Record (EMR) systems and the National Health Service mandated this in April 1999.
The October 2010 release contained 298,102 discrete concept codes of which 55,829 were marked as inactive, and 58,130 were pharmaceutical products or devices.
[6] Secondary care, including Mental Health and Dentistry, was mandated to move to SNOMED by April 2020.
[8] In August 2014 the ISB's successor, the Standardisation Committee for Care Information (SCCI), formalised the withdrawal time frame of Read version 2: A final updated release for Read version 2 is to be made available on 1 April 2016, and will be withdrawn completely on 1 April 2020.
[9] The Read Codes Drug and Appliance Dictionary (DAAD) was published for the final time on 1 April 2016, with data since being pulled from public circulation.
[11] The intent of NHS Digital is to migrate users to the Drugs and Medicines Dictionary (dm+d), which itself is based upon SNOMED CT.