Association between addressing antiseizure drug side effects and patient-reported medication adherence in epilepsy

Abstract

Background and aim: Adherence to treatment is a critical component of epilepsy management. This study examines whether addressing antiepileptic drug (AED) side effects at every visit is associated with increased patient-reported medication adherence.

Patients and methods: This study identified 243 adults with epilepsy who were seen at two academic outpatient neurology settings and had at least two visits over a 3-year period. Demographic and clinical characteristics were abstracted. Evidence that AED side effects were addressed was measured through 1) phone interview (patient-reported) and 2) medical records abstraction (physician-documented). Medication adherence was assessed using the validated Morisky Medication Adherence Scale-4. Complete adherence was determined as answering "no" to all questions.

Results: Sixty-two (25%) patients completed the interviews. Participants and nonparticipants were comparable with respect to demographic and clinical characteristics; however, a smaller proportion of participants had a history of drug-resistant epilepsy than nonparticipants (17.7% vs 30.9%, P=0.04). Among the participants, evidence that AED side effects were addressed was present in 48 (77%) medical records and reported by 51 (82%) patients. Twenty-eight (45%) patients reported complete medication adherence. The most common reason for incomplete adherence was missed medication due to forgetfulness (n=31, 91%). There was no association between addressing AED side effects (neither physician-documented nor patient-reported) and complete medication adherence (P=0.22 and 0.20).

Discussion and conclusion: Among patients with epilepsy, addressing medication side effects at every visit does not appear to increase patient-reported medication adherence.

Keywords: antiepileptic drug side effects; epilepsy; medication adherence.

Figure 1

Patient-reported reasons for incomplete adherence. Notes: Each bar shows the proportion of patients with incomplete adherence who did not comply for each specific reason. Thirty-one (91%) patients answered “yes” to the question: “Do you ever forget to take your AED?”; 16 (47%) patients answered “yes” to the question “Are you careless at times about taking your medications?”; 3 (8%) patients answered “yes” to the question “When you feel better, do you sometimes stop taking your medications?”; and 3 (8%) patients answered “yes” to the question “Sometimes, if you feel worse when you take your medicine, do you stop taking it?” The reasons are not mutually exclusive (ie, the same patient may report more than one reason for incomplete adherence). Abbreviation: AED, antiepileptic drug.

Figure 2

Physician-documented complete medication adherence (A); Patient-reported complete medication adherence (B). Notes: (A) Proportions of complete medication adherence among patients whose physician documented giving treatment counseling (ie, addressing AED side effects) or whose physician did not document giving treatment counseling. Of the 48 whose physicians reported counseling, 24 (50%) had complete adherence and 24 (50%) had incomplete adherence. Of the 14 whose physicians did not report counseling, four (29%) had complete adherence and ten (71%) had incomplete adherence. (B) Proportions of complete adherence among patients who reported receiving treatment counseling (ie, addressing AED side effects) or who reported not receiving treatment counseling. Of the 51 who reported receiving counseling, 21 (41%) had complete adherence and 30 (59%) had incomplete adherence. Of the eleven who reported not receiving counseling, seven (63%) had complete adherence and four (37%) had incomplete adherence. Abbreviation: AED, antiepileptic drug.