Adherence to anti-seizure medications in the Swedish Prospective Regional Epilepsy Database and Biobank for Individualized Clinical Treatment (PREDICT)

Abstract

The aim of this study was to describe the extent of, and risk factors for, non-adherence to anti-seizure medications (ASMs) in adult people with epilepsy (PWE) in Sweden. A cross-sectional multi-centre study was performed of PWEs in western Sweden, with data from medical records, and a questionnaire filled in by the participants including self-reports on how often ASM doses had been forgotten during the past year. Participants were categorized into adherent if they forgot at 0-1 occasion, and non-adherent if they forgot at 2-10 or >10 occasions. Demographic and clinical factors were compared by Chi2- or Fisher's test and a logistic regression model was used to find risk factors for non-adherence. In the cohort of 416 PWE aged median 43, IQR 29-62 years, 398 patients were prescribed ASM treatment at inclusion, and 39 % (n = 154) were in the non-adherent group. Significant factors in the multivariable analysis were: younger age, seizure freedom the past year, valproate treatment and experiencing side effects. The rate of self-reported non-adherence was high, illustrating a need for continuous focus on fundamental aspects of epilepsy care. The identified risk factors could enable quality improvement projects and patient education to be directed to those at risk of non-adherence.

Keywords: Adherence; Adverse effects; Antiepileptic drug; Compliance; Seizure; Therapy.

Fig. 1

(A) Map illustrating Västra Götaland County in Sweden, its municipality zones, and population density (inhabitants per square kilometre as of 2016). The public neurology units in the region are listed, along with the number of included cases per each of the five participating centres. Their catchment area is coloured in red scale, while the area of the 6th community hospital that chose not to participate is coloured in grey scale. (B) The age distribution of the 416 participants. (C) Gender distribution. (D) The participants’ epilepsy types.

Fig. 2

The question “Did you forget to take your ASM during the past year?” was included in the participant questionnaire. The pie chart shows percentages of the participants’ responses: Never, n = 189; 1 occasion, n = 51; 2–10 occasions, n = 133; >10 occasions, n = 21; Missing, n = 4.