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Clinical Classifications

OPCS-4 and ICD-10 are clinical classifications standards. Both are mandated nationally for use across the NHS and consist of groupings of concepts (codes), plus definitions and business rules for their use.

Access the clinical classifications standards

Visit our TRUD platform to download the clinical classifications data files and related content. You need to register for an account and accept the terms of all licenses associated with the materials you access.

Request a change to OPCS-4

Requests changes to OPCS-4 via the request submission portal. The deadline for submitting requests is 30 September 2021.

OPCS-4 Browser
The NHS Digital Classifications Browser allows you to browse and search OPCS-4.9 and OPCS-4.8 classification content and national clinical coding standards and guidance.

What the classifications are for

The clinical classifications enable statistical and epidemiological analysis and are used to reimburse hospitals for the care they have provided.

OPCS-4 is used to classify interventions and surgical procedures, while ICD-10 is used to classify diseases and other health conditions.

The classifications:

  • capture snapshots of population health at a point in time
  • provide insights on trends
  • inform public health investments
  • aid service planning
  • reimburse hospitals for the care provided

The classifications have a hierarchical structure, with sub-divisions to allow statistical presentation of data that enables meaningful and useful information to be obtained.

They also contain a constrained number of mutually exclusive categories to aid use in a statistical context and they reduce the possibility that events may be inadvertently excluded, or counted multiple times.

How classifications are used

In hospitals the classifications are used to classify information derived from patient records, at the end of each consultant episode of care.

There are currently over 19 million Finished Consultant Episodes per year for admitted patient care at NHS hospitals in England, or performed in the independent sector and commissioned by the English NHS.

Once the information is coded using these nationally mandated classifications, it is then used in an aggregated, non-identifiable form, to allow for statistical and epidemiological analysis, reimbursement of hospitals and planning of health and care services.

In England, the uses of the standards classifications are defined in the NHS Data Model and Data Dictionary. They are also a vital component of several national datasets, including:

Implementation details

In England, OPCS-4 and ICD-10 are fully implemented and embedded NHS standards, mandated for use by Health Care Providers. They form part of the NHS Standard Contracts and have been approved as NHS Fundamental Information Standards, by the Data Coordination board.  

They are typically updated every 3 years to aid the analysis of long-term statistical trends.

Management of standards

NHS Digital develops, maintains and licenses OPCS-4 on behalf of the Department of Health

NHS Digital, as the UK WHO-Family of International Classifications Collaborating Centre, contributes to the development and maintenance of ICD-10, which is owned by the World Health Organization (WHO). We have been granted a licence by WHO, to make ICD-10 available for use across the NHS.

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Last edited: 25 January 2023 11:01 am