Socioeconomic status and access to multiple sclerosis treatment in Mexico.

Introduction: Multiple sclerosis (MS) is a chronic neurological autoimmune condition and the leading non-traumatic cause of neurological disability worldwide. Disease-modifying therapies (DMT) directly impact on the long-term prognosis of patients with MS preventing relapses and the associated disability progression. Here, we analyzed the impact of socioeconomic status (SES) on DMT access in Mexican patients.

Methods: We evaluated the association between SES and DMT access using the MS registry from the National Institute of Neurology and Neurosurgery in Mexico City. We included 974 patients with MS (McDonald 2010 criteria). We categorized SES according to the 2018 Mexican Association of Market Research Agencies (AMAI) SES classification. We analyzed DMT type, MS phenotype, educational level, symptomatic onset to diagnosis, EDSS at arrival, as well as the progression index. Chi-squared and Wilcoxon tests were used, and multivariable analysis performed for DMT access.

Results: When comparing the lower versus higher levels of SES, a significant association was found on the percentage of patients with higher levels of disability (EDSS >6) at arrival, the proportion of patients not receiving any DMT and a higher proportion of secondary progressive MS (p=0.006, p<0.001and p=0.004, respectively). We also found that lower educational levels had a significance and inverse association with EDSS on first visit (p=0.019), symptomatic onset to diagnosis (p<0.001) and a higher disability status at arrival (EDSS >6, p=0.010).

Conclusions: Our study suggests that SES is an important factor determining not only prompt but overall access to highly effective DMT. Lower SES are associated with greater levels of disability at the first clinic visit and a higher proportion of patients not receiving DMT up to 12 months of follow-up.