Data Quality Webinar for General Practice Ian Spiers, Terminologist, NHS Digital

Data Quality Will be recording this session and if the recording is of a good enough quality we will publish the recording. I have Helen on the call as well who will help facilitate the webinar and questions.

Tools to be used Webinar is for you to have a discussion about data quality issues and approaches We will reference Data Quality Guidance Use Look-up for Read to SNOMED SNOMED CT Browser Today : Use 8 points from Data Quality Guidance to discuss Further Webinars will be based on feedback from Data Quality Leads on the Delen Forum

Discussion Points 1. Inactive Content 2. Terms ending in NOS / NEC 3. Abbreviations 4. Duplicate Terms 5. Outdated Terms 6. [ ] Terms 7. Terms that should be children but are not 8. Grouper Terms

Inactive Content Some Read codes are mapped to inactive SNOMED CT Acute bronchitis/bronchiolitis inactive in SNOMED CT - It is ambiguous Need to choose

Inactive Content Serum folate borderline is inactive in SNOMED CT It is ambiguous, do have Borderline low and Borderline high Need to choose

Inactive Content Terms with Clinic A / Clinic B have codes mapped to inactive SNOMED CT concepts These will map but to inactive codes; they are not interoperable, never went through GP2GP Different Practices will have different clinics Use specific clinic type administrative terms in future e.g. seen in asthma clinic, referral to asthma clinic

Inactive Content Some Read codes are mapped to inactive SNOMED CT Descriptions Need to choose

Terms ending in NOS / NEC Read terms ending in NOS (not otherwise specified) This also shows that Read had synonyms that not exactly true Otitis media is a type of middle ear disorder in SNOMED CT and not always infective Read terms ending in NOS (not otherwise specified), NEC (not elsewhere classified), NOC (not otherwise classified) or HFQ (however further qualified) and those beginning Other specified originated from the classifications (ICD and OPCS). The meanings intended by these pre- and postfixes are very specific: the meaning is also unique to one particular version of the classifications. ICD and OPCS are typically static for a number of years. These codes therefore serve as generic ‘catch alls’ for conditions that lack a dedicated code in the specific version of the classification. If a dedicated code for the condition is added to a later version of the same classification, then the meaning of these catch-all terms changes. SNOMED CT changes every 6 months, and is used for recording details at the point of care. As such these codes have no place in a patient record. When Read was first designed it took content from the classifications and so these catch-all terms also exist in Read; they have been used to code significant volumes of real patient data. The mapping tables therefore provide a map for such codes into SNOMED CT, with most mapping to a SNOMED synonym with the same text but without the NOS or NEC etc or, in the case of some typically very general codes, to text which is different but still reflects the same or very similar meaning

Terms ending in NOS / NEC Read terms ending in NEC (not elsewhere classified) Some map to exact term minus NEC – Vagotomy NEC Some map to slightly different text minus NEC but still means the same – Revision cerebrovent shunt Some map to a more “generic” term – Extracranial vagotomy NEC maps to Vagotomy Which has a synonym of Extracranial vagotomy operation

Abbreviations Because of the term length restrictions inherent to READ v2, some of its terms were abbreviated. By contrast, the aim to avoid ambiguity in SNOMED CT means that such Descriptions do not exist in SNOMED CT. The requirement on all system suppliers is to accommodate these longer descriptions in their system design. These abbreviated terms are mapped to an unabbreviated equivalent Most common clinical abbreviations do exist in SNOMED CT, and can be used to search for terms. They generally are a synonym and the full expansion of the abbreviation will normally also appear after the abbreviation, within the same Description – This is because some abbreviations are used in different specialties with different meanings with the same Abbreviation for example PID can be a pelvic inflammatory disease OR a prolapsed intervertebral disc.

Duplicate Terms There are a number of terms that are in Read twice; sometimes by mistake (we now have sophisticated software to check for duplicates at the authoring stage) or because it could be categorised in more than one way and so was placed in all possible appropriate locations. This means two Read codes may correctly map to the same SNOMED CT Concept, but consequently the SNOMED Description may have slightly different wording to the original Read terms.

Duplicate Terms There are a number of terms that are in Read twice; sometimes by mistake (we now have sophisticated software to check for duplicates at the authoring stage) or because it could be categorised in more than one way and so was placed in all possible appropriate locations. This means two Read codes may correctly map to the same SNOMED CT Concept, but consequently the SNOMED Description may have slightly different wording to the original Read terms.

Outdated Terms Diabetes mellitus is now described by whether it is type 1 or type 2 rather than the older convention of describing as Insulin or Non-Insulin dependent. Data entry should use terms with type 1 or type 2 for diabetes mellitus in Read v2.

[ ] Terms Read Codes with prefix [X], [SO], [M], [V], [Q], [D] All originate from classification type terms added to Read Codes beginning [X] exist as the same description without the [X] Codes beginning [SO] exist as the same description without the [SO] Codes beginning [M] exist as the same description without the [M]

Terms that should be children but are not Ran out of space in Read – 5 character codes C10E1 Type 1 diabetes mellitus with ophthalmic complications Ideally have the following as children C10EF Type 1 diabetes mellitus with diabetic cataract C10E7 Type 1 diabetes mellitus with retinopathy C10EP Type 1 diabetes mellitus with exudative maculopathy Some terms currently published in Read v2 should be classified under some existing level 5 term … but they cannot be because of the Read v2 hierarchy limit. Instead they have had to be represented used the fixed 5 character codes that Read v2 provides.

Grouper Terms Within Read v2 some codes exist that serve only to gather together codes related to the same clinical area so that they’re easier to find when using the hierarchy to pick a code for data entry. Therefore, they often gather together codes to record both when a given phenomenon is ‘present’ and when it is ‘not present’. This is NOT the case in SNOMED CT; codes where the symptom or condition is absent do exist in SNOMED but in a completely separate hierarchy . These grouper terms make it difficult to analyse data in Read as the children are a mix of codes

Collaborative space - Delen Further Webinars based on feedback from Data Quality Leads Use Delen CCG Nominated Leads - SNOMED CT in Primary Care SNOMED CT in Primary Care Trainers Workspace discussion forum for raising issues If you don’t have access email: snomedprimarycare@nhs.net

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