Medication adherence in multiple sclerosis as a potential model for other chronic diseases: a population-based cohort study. Issue 2 (5th February 2021)

• Record Type: Journal Article
• Authors: Evans, Charity; Marrie, Ruth Ann; Yao, Shenzhen; Zhu, Feng; Walld, Randy; Tremlett, Helen; Blackburn, David; Kingwell, Elaine
• Is Part Of: BMJ open. Volume 11:Issue 2(2021)
• Publication Date: 2021-02-05
• Subjects: multiple sclerosis -- general medicine (see internal medicine) -- epidemiology; Medicine -- Research -- Periodicals; 610.72
• DOI: 10.1136/bmjopen-2020-043930
• Languages: English
• ISSNs: 2044-6055

Abstract

Abstract : Objective: To determine whether better medication adherence in multiple sclerosis (MS) might be due to specialised disease-modifying drug (DMD) support programmes by: (1) establishing higher adherence in MS than in other chronic diseases and (2) determining if higher adherence is associated with patient-specific or treatment-specific factors. Design: Retrospective cohort study with data from 1 January 1996 to 31 December 2015. Setting: Population-based health administrative data from three Canadian provinces. Participants: Individual cohorts were created using validated case definitions for MS, epilepsy, Parkinson's disease (PD) and rheumatoid arthritis (RA). Subjects were included if they received ≥1 dispensation for a disease-related drug between 1 January 1997 and 31 December 2014. Main outcome measure(s): Proportion of subjects with optimal adherence (≥80%) measured by the medication possession ratio 1 year after the index date (first dispensation of disease-related drug). Results: 126 478 subjects were included in the primary analysis (MS, n=6271; epilepsy, n=55 739; PD, n=21 304; RA, n=43 164). Subjects with epilepsy (adjusted OR, aOR 0.29; 95% CI 0.19 to 0.45), PD (aOR 0.42; 95% CI 0.29 to 0.63) or RA (aOR 0.26; 95% CI 0.19 to 0.35) were less likely to have optimal 1-year adherence compared with subjects with MS. Within the MS cohort, adherence was higher for DMD than for chronic-use non-MS medications, and no consistent patient-related predictors of adherence were observed across all four non-MS medication classes, including having optimal adherence to DMD. Conclusions: Subjects with MS were significantly more likely to have optimal 1-year adherence than subjects with epilepsy, RA and PD, and optimal adherence appears related to treatment-specific factors rather than patient-related factors. This supports the hypothesis that higher adherence to the MS DMDs could be due to the specialised support programmes; these programmes may serve as a model for use in other chronic conditions.