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Coding Information for Analysts

Terminology Services and Clinical Coding

NHS National Services Scotland ISD Scotland & NHS National Services Scotland

Coding Information for Analysts

Terminology Services offer clinical coding training, advice and expertise to all NHS Scotland staff. This includes provision of coding and terminology awareness sessions for information analysts. The Service also provides an expert led Terminology Advisory Service which operates Tuesday-Thursday (see contact details below). We manage the introduction of new and updated nationally approved classifications and terminologies on behalf of the NHS in Scotland and liaise with other UK coding and terminology colleagues. We can also make requests for new codes for existing terminologies and classifications (SNOMED CT and OPCS). The team has expertise in ICD-10 and OPCS-4 classification systems and Read and SNOMED CT terminologies.


Terminology Services run a number of courses aimed at analysts (NSS analysts, other health board analysts or researchers):

  • Classifications and SMR dataset awareness - half-day - this is required training for all analysts involved in analysing ICD-10 and OPCS coding. The course also gives an introduction to the SMR datasets.
  • Read Terminology awareness - half-day
  • SNOMED CT terminology awareness - half-day

Discuss your training needs with your manager. Once approved your manager should contact the Terminology Helpdesk to request training.


One important function of Terminology Services is to identify the correct codes for answering Information Requests (IRs) or Parliamentary Questions (PQs). Customer requests may not be as straightforward as they appear and it is important to ensure that the right questions are being asked of the customer. This often requires specialist coding knowledge and Terminology Services staff can assist you in this process. Also coding systems and guidance are constantly being updated, so even if you have a request for repeated analyses it is important to always check with Terminology Services to ensure that no new codes are being omitted from the search. We can also provide mapping assistance for longitudinal studies where coding systems may have substantially changed during the time period of the analysis e.g. ICD-9 to ICD-10 change in April 1996. If you are an analyst with an information request, please provide the original customer question to help with the query. Also, please let us know if it is a press enquiry, a Freedom of Information or a parliamentary question, and when the data is required.

Checklist for before you contact the Terminology Advisory Service Helpdesk:

  1. What is the time period for the analysis? Are there any restrictions on age/sex?
  2. What is the customer's original question or aim in asking for the analysis?
  3. Details of the approach the analyst is planning to take in answering the question (for example do they need diagnosis and/or procedures).
  4. What type of SMR coding schemes are being queried?
  5. Do you want all codes which fit that description or only those which definitely do? Under certain circumstances the index leads to a code whose category title is not the original description. It is then up to the customer whether these codes are included.
  6. For mapping exercises (e.g. ICD-10 - ICD-9) are the codes required individually or in blocks?
  7. For some more complex analysis it is necessary to feeback suggestions to the customer and so they need to be aware that this is an iterative approach.
  8. Deadline for Terminology Services to get back to the analyst.
  9. Deadline for the customer.
  10. Details of any reference number - particularly the IR number.

Above all it is really important that you involve us as early as possible in any projects, Information Request or PQs involving any of the above mentioned coding schemes.

The helpdesk is open Tuesday-Thursday 9am to 5pm on 0131 275 7283. You can also send non-urgent requests by email to The email inbox is checked on active helpdesk days. However analysts with urgent requests (requiring an answer within 24hrs) and PQs should contact the telephone helpdesk directly. Outwith the helpdesk hours, urgent requests should go through the Terminology Services Manager.

* It is important when using coding and terminology reference material and tools that you ensure that your reference source matches the currently approved version for use in NHS Scotland. If not, you may end up searching for inadmissible codes which could lead to inaccurate analyses or incorrect interpretation of the data.. Coding for IRs and PQs should always be verified with staff on the Terminology Advisory Service before proceeding with an analysis.

For NSS analysts the Read terminology browser can be obtained from NSS IT helpdesk. For information on all our terminology and classification tools please see our Classification and Terminology Tools page.


Using the Coding Guidelines

Terminology Services publishes and disseminates coding decisions and advice approved by the ISD Clinical Coding Review Group (which includes medical, analytical and Terminology Services representation). These are issued approximately every 6 months (March and September) as NHS Scotland Clinical Coding Standards. All standards are available from Terminology Services webpages and will also be available on the ACaDMe Metadata system. The guidance informs on coding clarifications, changes to coding practice and updates to coding systems. It is important to consult these when considering codes for analyses as codes or coding practice may change. In addition to the standards there is a cumulative index of all standards (current and obsolete) - however this does not contain details of the changes. For all current standards there is a consolidation document available for ease of use. However this will not provide information on previous guidance and may be of limited use if you are carrying out longitudinal analysis.

Classification updates
From time to time both OPCS-4 and ICD-10 are updated across NHS Scotland - in recent years this has been according to a three year schedule - one type each year and one year without changes. The implementation of these updates across NHS Scotland is managed by the Terminology Services team and the decision to update is taken by a PHI project team led by Terminology Services. It should be noted that updates do not always occur in the same year as updates in the rest of the UK. The most recent updates to both classifications in NHS Scotland are listed in the table below:

ICD Version Time Period
ICD-7 1961-67
ICD-8 1968-1979
ICD-9 1980-March 1996
ICD-10 April 1996* (*1995 in England)
ICD-10-v4 April 2013* (*2012 in England)
ICD-10-v5 April 2016
OPCS version Time Period
GRO 1961-70
OPCS2 1971-76
OPCS3 1977-88
OPCS-4 1989-2006
OPCS-4.3 April 2006
OPCS-4.4 April 2007
OPCS-4.5 April 2009
OPCS-4.6 April 2011
OPCS-4.7 April 2014
OPCS-4.8 April 2017

Scottish English coding differences
It is important to note when benchmarking with NHS England that there are many differences in how Scotland and England apply coding in practice as well as some differences in dates of update. For advice on the main differences please contact our helpdesk.



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Information Services Division,
NHS National Services Scotland,
Gyle Square,
1 South Gyle Crescent,
Edinburgh EH12 9EB,
Tel: 0131 275 7050  
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