Abstract: We included 12 studies reporting data on 1642 participants (intervention = 833, control = 809). Eight studies targeted adults with epilepsy, one study included participants of all ages, one study included participants older than two years, one study targeted caregivers of children with epilepsy, and one study targeted families of children with epilepsy. We identified six ongoing trials. Follow-up time was generally short in most trials, ranging from one to 12 months. The trials examined three main types of interventions: educational interventions, behavioural interventions and mixed interventions. All studies compared treatment versus usual care or 'no intervention', except for two studies. Due to heterogeneity between studies in terms of interventions, methods used to measure adherence and the way the studies were reported, we did not pool the results and these findings were inappropriate to be included in a meta-analysis. Education and counselling of participants with epilepsy resulted in mixed success (moderate-quality evidence). Behavioural interventions such as use of intensive reminders provided more favourable effects on adherence (moderate-quality evidence). The effect on adherence to antiepileptic drugs described by studies of mixed interventions showed improved adherence in the intervention groups compared to the control groups (high-quality evidence). Behavioural interventions such as intensive reminders and the use of mixed interventions demonstrate some positive results; however, we need more reliable evidence on their efficacy, derived from carefully-designed randomised controlled trials before we can draw a firm conclusion. Since the last version of this review, none of the new relevant studies have provided additional information that would lead to significant changes in our conclusions. This current update includes 12 studies, of which six came from the latest searches.

Plain-language summary: We searched scientific databases for clinical trials looking at ways of improving adherence to drug treatment in people with epilepsy. We limited our search to randomised controlled trials involving people with a clinical diagnosis of epilepsy of any age and treated with antiepileptic drugs in a primary care, outpatient or other community setting. The results are up-to-date to February 2016. We identified twelve trials (1642 participants). The trials were conducted in different countries with the majority from the United States. The trials examined three main types of interventions: i) education and counselling of participants about topics such as epilepsy and medication used to control epilepsy, ii) behavioural interventions such as asking epileptic patients to link the intention of taking their medication with a particular time, place and other routine activity and iii) the use of more than one intervention (mixed interventions). Behavioural interventions and mixed interventions resulted in an improved adherence in the intervention groups compared to the control groups. Four trials showed that when adherence improved in the intervention groups, seizure frequency or seizure severity was decreased. Many of the included trials are of moderate quality and have limitations in the design. Therefore, it is difficult to draw firm conclusions. We need carefully-designed randomised controlled trials involving more people with longer follow-up periods to identify the best intervention to improve adherence to antiepileptic medication.