IntroductionPrimary healthcare records are used for studies within large data repositories. One of the limitations of using these routinely collected data for epilepsy research is the possibility of including incorrectly recorded diagnoses. To our knowledge, the accuracy of UK GP diagnosis codes for epilepsy has only partially been validated. Objectives and ApproachWe aimed to validate the accuracy of case ascertainment algorithms in identifying people with epilepsy in routinely collected Welsh healthcare data. A reference population of 150 people with definite epilepsy and 150 people without epilepsy was ascertained from hospital records and linked to records held within the Secure Anonymised Information Linkage (SAIL) databank in Wales. We used three different algorithms to identify the reference population: a) individuals with an epilepsy diagnosis code and two consecutive AED prescription codes; b) individuals with an epilepsy diagnosis code only; c) individuals with two consecutive AED prescription codes only. ResultsWe applied the algorithms to all patients and to adults and children separately. For all patients, combining 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). This can be explained by the widespread use of AEDs for indications other than epilepsy in adults, which is not the case for children. Conclusion/ImplicationsGP epilepsy diagnosis and AED prescription codes can be used to identify people with epilepsy using anonymised healthcare records in Wales. In children using AED prescription codes alone is an accurate way to identify epilepsy cases. These results are generalizable to other studies that use UK primary care records.

No abstract

Background Several studies linked the use of levodopa to an increase in homocysteine level, which can lead eventually to ischemic heart disease (IHD) in Parkinson’s disease (PD) patients. There is a lack of large population studies that have investigated the cardiovascular safety of levodopa. Objectives The main objective of the study is to investigate the one-year risk of IHD hospitalisation, all-cardiovascular hospital hospitalisation, and all-cause mortality among users of L-dopa compared with users of Monoamine oxidase B (MAO-B) inhibitors (as a reference). Methods A population-based study evaluated data obtained from the Secure Anonymised Information Linkage (SAIL) Databank of residents in Wales, aged 40 years or older, newly treated with PD medications between 2000 and 2016. The General Practice (GP) database was used to identify the PD diagnostic codes, PD medications, and other medications used by PD patients. Hospital data were used to identify the first hospitalisation event (IHD and other cardiovascular events). A fully adjusted propensity score multivariate Cox regression analysis was used to examine associations between levodopa and the study outcomes. The index date was set at the date of the first PD prescription in the newly diagnosed PD patients. Other variables included gender, comorbidities, social deprivation score and previous medications history were controlled for. Findings There were 5,140 participants on levodopa and 494 on MAO-B inhibitors. L-dopa was not associated with IHD (p=0.561), other cardiovascular events (p=0.233), or all-cause mortality (p=0.334). For IHD, the lack of difference was seen also in the unadjusted model and in the age-only adjusted model. Conclusion This study has shown that L-dopa does not increase the risk of IHD, cardiovascular risk, or all-cause mortality in the newly diagnosed PD patient within one year after the therapy initiation. This could contribute to the safety profile of L-dopa therapy. Future research with a longer follow up period is warranted.