DARWIN EU© is an initiative created by the European Medicines Agency (EMA) to generate timely evidence from real-world healthcare data sources from across Europe.
The EMA has requested a study to estimate how often, with what strengths, and for how long valproate, a medicine to prevent seizures in patients with epilepsy, is being used in women of childbearing age. Valproate is known to cause harm for the unborn child when used during pregnancy. Therefore, its use in young women is restricted. However, for certain types of epilepsy valproate-containing medication might be the most effective therapy.
As timely information on the use of valproate in young women across Europe is important, the objective of this study is to estimate the new users (also called incidence rate) and existing users (prevalence) of valproate-containing medicines and other drugs used to prevent seizures. Secondly, we will look at the reasons for prescribing valproate-containing medication, and for how long and at what strength they are prescribed. We will also explore characteristics of patients prescribed/dispensed valproate in terms of comorbidity and concomitant drug use.
Background: Primary care records provide a unique source of data for estimating drug utilisation in the community. The DARWIN EU© initiative created by the European Medicines Agency (EMA) intends to draw upon such data to inform regulatory decision-making, and has requested a drug utilisation study on valproate-containing medications and other anti-epileptic drugs in women of childbearing age.
Valproate-containing medicines (VPA) are used for prevention of seizures in people with epilepsy, as alternative treatments for the treatment of bipolar disorder, and for migraine prevention. Valproic acid is a teratogen, with prenatal exposure carrying a substantial risk for the unborn child. Therefore, its use in women of childbearing age is restricted. Timely information on the use of VPA in young women across Europe is important to inform regulatory decision making and risk minimization programs.
Study design: Cohort study
Population: All women aged between 12 years and ≤55 years between 2010 and 2021 people in CPRD GOLD with >=1 year of prior history will be eligible for study inclusion. For the characterisation of new VPA users, VPA must not have been used in the prior year.
Drug(s) of interest: VPA and alternative treatments
Variables: Exposure to VPA and alternative treatments will be based on prescription data in CPRD GOLD [product codes mapped to the OMOP Common Data Model].
In addition, the characteristics of patients being prescribed VPA will be summarised, and the use of VPA over time will be assessed in terms of indication of use, duration, strength and/or dose.
Analyses:
1) Estimation of annual period prevalence and annual incidence rates of VPA use and alternative treatments.
2) Characterisation of new VPA users, including medical history and co-medication use. Frequency of indication, namely epilepsy, bipolar disorder and migraine at index date will be assessed. Initial dose/strength and treatment duration will be estimated.
Drug utilisation: Incidence and Prevalence of VPA and alternative treatments; Characterisation of new VPA users
Daniel Prieto-Alhambra - Chief Investigator - University of Oxford
Annika Jodicke - Corresponding Applicant - University of Oxford
Albert Prats Uribe - Collaborator - University of Oxford
Edward Burn - Collaborator - University of Oxford
Junqing Xie - Collaborator - University of Oxford
Martí Català Sabaté - Collaborator - University of Oxford
Mike Du - Collaborator - University of Oxford
Xintong Li - Collaborator - University of Oxford
Yuchen Guo - Collaborator - University of Oxford
Daniel Prieto-Alhambra - Collaborator - University of Oxford