Adherence to treatment, a challenge even in treatable metabolic rare diseases: A cross sectional study of Wilson's disease.

Wilson's disease (WD), a rare genetic disorder responsible for copper accumulation in the body, is fatal if left untreated. Although there are effective treatments, adherence to treatment tends to be low. We evaluated the medication adherence of 139 patients using the Morisky scale. Adherence was correlated with age at diagnosis and at inclusion in the study, the form of the disease, the treatment, the duration of treatment, delivery and storage problems, depression, anxiety, the level of education, and the biological data. 32.4% of the patients had low adherence; their levels of exchangeable copper were significantly higher than those of the patients with high or medium adherence (P = .049). The average age of the patients at the time of the study was significantly higher in those with high adherence than in those with medium or low adherence (P = .043). 75.9% of the patients with high adherence had a neurological form and 26.7% of the patients with low adherence were asymptomatic (P = .0090). The duration of treatment was significantly longer in the patients with high adherence than in those with medium or low adherence (P = .0192). The type of treatment (chelators or zinc) had no impact on the level of adherence. Forty-four percent of the patients experienced problems dispensing and storing medications. Despite the availability of effective treatments for this rare disease, adherence problems occur with Wilson's disease in particular in asymptomatic patients. Although different factors are involved, sustained multidisciplinary management on a case-by-case basis is necessary.