Comorbidity and persistence of disease-modifying therapy use for relapsing remitting multiple sclerosis
Comorbidity may impact use of disease-modifying therapies (DMTs) among individuals with relapsing remitting multiple sclerosis (RRMS). Our objectives were to characterize the relationship between comorbidity and (1) persistence to initial DMT, (2) choice of DMT, and (3) reasons for DMT discontinuation. We identified individuals with RRMS/clinically isolated syndrome (CIS) starting platform DMT as initial therapy from 2001 to 2016 using a clinic database. Among 1464 individuals with RRMS/CIS beginning platform therapy as initial DMT, median duration of DMT persistence was 4 years. There was no effect of comorbidity count on DMT persistence. Mental health comorbidity increased risk of discontinuing DMT. Prior to 2013 when platform therapy consisted of only injectable DMT options, there was increased selection of glatiramer acetate compared to interferon-β among those with ≥2 comorbidities. There was increased risk of discontinuing initial DMT for lack of tolerability with ≥2 comorbidities.