Correlation between adherence to antiepileptic drugs and quality of life in patients with epilepsy: A longitudinal study

Objective: This study aimed to investigate whether the score of self-reported medication adherence using the Medication Adherence Report Scale (MARS-5) correlates with the serum level of antiepileptic medication, as well as whether the MARS-5 score can predict the quality of life (QoL) in patients with epilepsy. Methods: A longitudinal study was carried out. The patients with epilepsy who were prescribed a minimum of one antiepileptic drug were recruited (n = 807). Each participant completed a background information sheet and the MARS-5 at baseline, followed by the Liverpool Seizure Severity Scale (LSSS) and Quality of Life in Epilepsy (QOLIE-31) questionnaire at 18-month follow-up. In addition, the serum level of antiepileptic medications was measured at the follow-up. Results: The MARS-5 score was negatively associated with the LSSS score (B = -0.089, SE = 0.009, p < 0.001) and positively correlated with the serum level of antiepileptic medications (B = 3.200, SE = 0.416, p < 0.001), after adjusting for demographics and clinical characteristics. The serum level of antiepileptic drugs was significantly correlated with the overall QOLIE-31 score (B = 3.118, SE = 1.417, p = 0.03). The MARS-5 score was significantly correlated with the overall QOLIE-31 scores and all the scores in the subcategories. In addition, the MARS-5 score was in line with the correlation between the LSSS and QOLIE-31 scores (Z = 4.20, p < 0.001) and between serum antiepileptic medication levels and QOLIE-31 score (Z = 3.98, p < 0.001). Conclusions: The MARS-5 score can predict the QoL in patients with epilepsy for up to 18 months. Therefore, healthcare providers may predict the QoL and drug adherence using the MARS-5 score, in order to design personalized interventions. (C) 2016 Elsevier Inc. All rights reserved.