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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

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Request a change to OPCS-4

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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 standards are for

The standards focus on statistical and epidemiological analysis. They are used to reimburse hospitals for the care they have provided. OPCS-4 is used to classify interventions and surgical procedures, ICD-10 is used to classify diseases and other health conditions.

The standards:

  • capture snapshots of population health at a point in time. They provide insight on trends, inform public health investments, aid service planning and reimburse hospitals for the care provided
  • have a hierarchical structure, with sub-divisions to allow statistical presentation of data, to enable meaningful and useful information to be obtained
  • and contain a constrained number of mutually-exclusive categories to aid use in a statistical context. They reduce the possibility that events may be inadvertently excluded, or counted multiple times.

How standards are used

The standards are used by clinical coders to classify information derived from patient records, at the end of each hospital-provider 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 national standards, 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 are defined in the NHS Data Model and Data Dictionary and specifically in the Admitted Patient Care Commissioning Data Set. They are also a vital component of several national datasets, including:

Implementation details

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 updated every three 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 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: 17 April 2020 1:34 pm