Medication non-adherence in essential tremor

Background: There are numerous studies of medication adherence in a variety of chronic diseases including Parkinson's disease; however, there are no such studies in patients with essential tremor (ET). This study aimed to (1) present self-report data on medication adherence in ET cases, (2) examine the demographic and clinical factors that might be associated with lower medication adherence. Methods: 151 ET cases were enrolled in a clinical-epidemiological study at Columbia University. An 11-item medication adherence questionnaire, modeled after the Morisky medication adherence questionnaire, was administered. Results: Seventy-three (48.3%) of 151 cases were taking daily medication for ET. One-third (24/73; 32.9%) of cases reported that they sometimes forgot to take their medication, and 1 in 5 (15/73; 20.5%) reported missed doses within the past week. Most striking was that nearly 1 in 4 (17/73; 23.3%) reported that there were whole days in the past two weeks in which they had not taken their medication. A factor analysis revealed four factors that captured different aspects of non-adherence. Higher non-adherence was associated with more depressive symptoms, younger age, and less severe tremor but was not associated with type or number of ET medications. Conclusions: Approximately one in four ET patients reported whole days in the past two weeks in which they had not taken their medication. It is possible that this relatively high rate of non-adherence could be a function of the poor therapeutic efficacy of the medications currently available to treat ET.