Metadata Files


    Files Available
  1. Metadata files are used by the NHS to validate data. The files facilitate data consistency and quality. The files are:

    • Diagnosis (ICD-10)

    • Operation (OPCS-4) Fourth Revision Consolidated Version

    • NHS Postcode Directory

    • Frozen Postcode Directory

    • Country Pseudo Postcodes.
  2. The ICD-10 file is issued by the NHS Information Authority, from whom a specification is available. It is intended to reissue this file in line with the ICD-10 updates.

  3. The Operation metadata file is also issued by the NHS Connecting for Health on request. No update of this file is currently envisaged.

  4. The NHS Postcode Directory (''Gridlink" version) is maintained, on behalf of the Department of Health, by the Office for National Statistics (ONS). The full NHS Postcode Directory on CD-ROM and via the NHSnet is provided free to the NHS, every quarter, by the National Administrative Codes Service (NACS). A reduced version of the full NHS Postcode Directory, containing Postcode, Strategic Health Authority Code and Primary Care Trust/Care Trust Code, is provided every quarter on CD-ROM and via NHSnet as part of the standard National Administrative Codes Service (NACS) data issue; see Publication Information Contact Details.

  5. A version of the Central Postcode Directory (CPD), the 91-based Frozen Postcode Directory, is produced by the ONS to provide a stable base to facilitate time source analysis. Full details are set out in the CPD User Guide available from ONS; see Publication Information Contact Details.

  6. Any area within the NHS taking advantage of the supply of metadata by ONS will be expected to abide by any rules and conditions imposed by the ONS Section supplying the metadata.

  7. Media
  8. NHS Connecting for Health Metadata files are normally supplied on disk. Potential users should contact the NHS Connecting for Health Coding and Classification Help Desk on 0121 333 0420 (direct line).

  9. Format of Metadata Files
  10. The following pages give the record layouts and data content for the Operation and Country Pseudo Postcode metadata files.

  11. Operation File Data Content
  12. This file consists of about 7,000 records, one record for each operation (OPCS-4) Fourth Revision Consolidated Version used in the HES processing system. The records are in operation code order. Each record also contains editing parameters used in validation.


    Start Position Size Occurs Field Description
    1 11   selection indicators
    12 1   operation prefix
    13 4   operation code
    17 8   filler
    25 55   operation name (3 digit)
    80 5   filler
    85 60   operation name (4 digit)
    145 43   filler
    188 1   sex (absolute)
    189 3   filler
    192 1   sex (scrutiny)
    193 1   filler
    194 2   status of operation
    196 23   filler
    219 1 10 method of delivery
    229 24   filler


    Field Content
    Operation Prefix space
    Operation Code 4 chars, 1 alphanumeric + 3 numeric
    Sex (absolute) space = accept any sex code
    1 = males not accepted
    2 = females not accepted
    1 = males not accepted
    2 = females not accepted
    Sex (scrutiny) space = accept any sex code
    1 = males not accepted
    2 = females not accepted
    NB The following relate to primary operation only
    Status of Operation if status not = 01, reject for scrutiny
    Method of Delivery 10 one character codes representing the DELMETH code values 0 - 9. Check character position corresponding to DELMETH code value
    space = no check required
    1 = reject for scrutiny
    Country Pseudo Postcode File Data Content
  14. This file contains about 130 records. The usual country of residence for short term overseas visitors is derived from the country pseudo postcode, these can be found by browsing the: NACS NHSnet website. The codes are also available in electronic format on the NHS Postcode Directory ("Gridlink" version).

  15. For the NACS contact details, see Publication Information Contact Details.

  16. The expanded area code field contains the country of birth code in characters 1-4 (a repeat of the characters 3-6 in the pseudo postcode). The remainder of the expanded area code is blank except for codes 993C (UK nos) and 993V (no fixed abode) where characters 5-7 are 9space9.


    Start Pos Size Data Type Field Description
    1 11 X selection indicators
    12 6 X 6 digit postcode (POSTSIX)
    18 1 A 7th digit
    19 6 X filler
    25 50 X name of country
    75 5 X filler
    80 19 X area details
    99 154 X filler