Validating epilepsy diagnoses in routinely collected data

Beata Fonferko-Shadrach,Arron S Lacey,Catharine P White,H.W Rob Powell,Inder M.S Sawhney,Ronan A Lyons,Phil E.M Smith,Mike P Kerr,Mark I Rees,W Owen Pickrell

doi:10.1016/j.seizure.2017.10.008

Abstract

PurposeAnonymised, routinely-collected healthcare data is increasingly being used for epilepsy research. We validated algorithms using general practitioner (GP) primary healthcare records to identify people with epilepsy from anonymised healthcare data within the Secure Anonymised Information Linkage (SAIL) databank in Wales, UK. MethodA reference population of 150 people with definite epilepsy and 150 people without epilepsy was ascertained from hospital records and linked to records contained within SAIL (containing GP records for 2.4 million people). We used three different algorithms, using combinations of GP epilepsy diagnosis and anti-epileptic drug (AED) prescription codes, to identify the reference population. ResultsCombining diagnosis and AED prescription codes had a sensitivity of 84% (95% ci 77–90) and specificity of 98% (95–100) in identifying people with epilepsy; diagnosis codes alone had a sensitivity of 86% (80–91) and a specificity of 97% (92–99); and AED prescription codes alone achieved a sensitivity of 92% (70–83) and a specificity of 73% (65–80). Using AED codes only was more accurate in children achieving a sensitivity of 88% (75–95) and specificity of 98% (88–100). ConclusionGP epilepsy diagnosis and AED prescription codes can be confidently used to identify people with epilepsy using anonymised healthcare records in Wales, UK.

Highlights

Vast amounts of electronic, routinely-collected, medical and related administrative data are generated in modern healthcare systems
Every individual in the United Kingdom (UK) is entitled to register with a primary care General Practitioner (GP) and there is evidence that almost everyone in the UK does register with a GP [6]
GPs have a central role in providing primary care for people with epilepsy through assessment, diagnosis, appropriate referral to secondary and tertiary services, managing and prescribing medications and creating and maintaining a centralised health care record

Summary

Introduction

Routinely-collected, medical and related administrative data are generated in modern healthcare systems. These data can be anonymised, linked and used for healthcare research [1,2]. Routinely-collected data are increasingly being used for high quality epilepsy studies [3,4,5]. GPs have a central role in providing primary care for people with epilepsy through assessment, diagnosis, appropriate referral to secondary and tertiary services, managing and prescribing medications (including the vast majority of anti-epileptic drugs) and creating and maintaining a centralised health care record. GP health records contain details of encounters with GPs and other healthcare providers using Read codes

Methods

Discussion

Conclusion