COVID identification in primary care - probable covid - positive test

Coding system
CTV3 (Read V3)
Codelist ID


Codes indicating COVID-19 case (1 of 13 possible types of CTV3 codes that contain information related to COVID-19)


Search of TPP CTV3 codes for terms relating to coronavirus, with additional (manual) check for any missing terms against the SNOMED list of COVID-19 related codes.

Classification as "case" was then performed following review of terms by six OpenSAFELY team members (including epidemiologists, clinicians, statisticians and infectious disease modellers).


Signed off by

  • Krishnan Bhaskaran, LSHTM (July 16, 2020)
  • Laurie Tomlinson, LSHTM (July 16, 2020)

This definition has been computed by taking the manually created full codelist and converting it to a list of rules that define the codelist.

CTV3ID CTV3PreferredTermDesc CTV3Source
XaLTE Coronavirus nucleic acid detection
Y20d1 SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) RNA (ribonucleic acid) detection result positive
Y213a Antigen of 2019-nCoV (novel coronavirus)
Y228d Coronavirus disease 19 caused by severe acute respiratory syndrome coronavirus 2 confirmed by laboratory test (situation)
Y23f7 SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) detection result positive
Y240b SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) RNA (ribonucleic acid) qualitative existence in specimen

Codes in the definition are underlined. Codes in the full codelist are in blue. Related codes not in the codelist are in black.