1. Overview

    Phenotype Type
    Disease or syndrome
    Sex
    Both
    Valid Event Date Range
    No data
    Coding System
    ICD10 codesRead codes v2Med codesSNOMED CT codesPROD codesBNF codesICD9 codesdm+d codes
    Data Sources
    CPRD GOLD
    CPRD Aurum
    Welsh Longitudinal General Practice Dataset (WLGP) - Welsh Primary Care
    Hospital Episode Statistics Admitted Patient Care
    Patient Episode Dataset for Wales (PEDW)
    Collections
    No data
    Tags
    No data
    Ontology
    epilepsy

  2. Definition

    This algorithm combines primary care and secondary care data in the UK to acurately identify cohorts with epilepsy.

    The algorithm may be applied in primary care or hospital data alone, but the highest sensitivity algorithms include both data sets.

    Epilepsy incidence dates should be calculated as a further step, once the case has been established.

    Note that we have also included lists of codes that we have identified and excluded from our lists.

    References:

    This work builds on that previously done by:

    Fonferko-Shadrach B, Lacey AS, White CP, Powell HWR, Sawhney IMS, Lyons RA, Smith PEM, Kerr MP, Rees MI, Pickrell WO. Validating epilepsy diagnoses in routinely collected data. Seizure. 2017 Nov;52:195-198. doi: 10.1016/j.seizure.2017.10.008. Epub 2017 Oct 13. PMID: 29059611; PMCID: PMC5703030.

  3. Implementation

    Implementation

    Assertaining cohorts with epilepsy

    In order to best assertain adult (>\\=16yrs) cohorts of individuals with epilepsy we would reccomend that the algorithm is applied using the following methods.

    This method combines prescribing data with epilepsy codes. Note that there are different types of codes used to define epilepsy contained here. Note also that genetic syndromes with associated epilepsy are included as 'epilepsy diagnostic codes', due to their high sensitivity for epilepsy when used in combination with ant-seizure medications. This code lists should be re-visitied if you intend to use the diagnostic codes without anti-seizure medications.

    Note that the linked validation paper also includes multiple alternative methods and code combinations.

    Reccomended algorithm for adults >\=16 years: 2 anti-seizure medication prescriptions in 6 months from the attached lists AND an epilepsy code (any type) in EITHER primary care or hospital data, within +/- 12 months

    Reccomended algorithm for children \<16 years: an epilepsy code (diagnostic only) in EITHER primary care or hospital data

    Assertaining epilepsy incidence date

    Electronic prescribing in the UK was introduced from 1985 onwards. Therefore, by definition no individual can meet the algorithm until after 1985. The majority of practices did not introduce electronic prescribing until 1990 onwards.

    Therefore we would reccomend that in cases identified by the algorithm, the earliest dates is taken of: First diagnostic epilepsy code in primary care, first diagnostic epilepsy code date in hospital data, first prescription of 2 anti-seizure medications in 6 months.

    Note that if you do not do this, and use only the date at which the algorithm is first met, you risk missclassification of onset - this risk should be considered even if you are only using more recent data - as a failure to identify the original onset date can lead to later misclassification.

  4. Clinical Codelist

  5. Publication

    Related publications

    No known publications

    Citation Example

    Kathryn J. Bush, Beata Fonferko-Shadrach, Huw A. Strafford, Arron S. Lacey, Andrew Kingston, Rhys H. Thomas, Sheena E. Ramsay, William O Pickrell. PH1928 / 4528 - Epilepsy (all) (and incident epilepsy with incidence date). Phenotype Library [Online]. 21 November 2025. Available from: http://phenotypes.healthdatagateway.org/phenotypes/PH1928/version/4528/detail/. [Accessed 19 August 2026]

  6. API

    To Export Phenotype Details:

    FormatAPI
    JSON site_root/api/v1/phenotypes/PH1928/version/4528/detail/?format=json
    R Package

    # Download here

    library(ConceptLibraryClient)


    # Connect to API

    client = ConceptLibraryClient::Connection$new(public=TRUE)


    # Get details of Phenotype

    phenotype_details = client$phenotypes$get_detail(
     'PH1928',
     version_id=4528
    )

    Py Package

    # Download here

    from pyconceptlibraryclient import Client


    # Connect to API

    client = Client(public=True)


    # Get details of Phenotype

    phenotype_detail = client.phenotypes.get_detail(
     'PH1928',
     version_id=4528
    )

    To Export Phenotype Code List:

    FormatAPI
    JSON site_root/api/v1/phenotypes/PH1928/version/4528/export/codes/?format=json
    R Package

    # Download here

    library(ConceptLibraryClient)


    # Connect to API

    client = ConceptLibraryClient::Connection$new(public=TRUE)


    # Get codelist of Phenotype

    phenotype_codelist = client$phenotypes$get_codelist(
     'PH1928',
     version_id=4528
    )

    Py Package

    # Download here

    from pyconceptlibraryclient import Client


    # Connect to API

    client = Client(public=True)


    # Get codelist of Phenotype

    phenotype_codelist = client.phenotypes.get_codelist(
     'PH1928',
     version_id=4528
    )

  7. Version History

    Version IDNameOwnerPublish date
    4530 Epilepsy (all) (and incident epilepsy with incidence date) kathryn.bush2025-11-24 09:17
    Epilepsy (all) (and incident epilepsy with incidence date) kathryn.bush2025-11-21 13:29
    4527 Epilepsy (all) (and incident epilepsy with incidence date) kathryn.bush2025-11-21 13:25
    4510 Epilepsy (all) (and incident epilepsy with incidence date) kathryn.bush2025-11-19 15:09
    4491 Epilepsy (all) (and incident epilepsy with incidence date) kathryn.bush2025-11-18 16:41