A nonparametric propensity score to estimate the effect of beta interferon or glatiramer acetate on long-term outcomes in multiple sclerosis
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Mult Scler Relat Disord. May 30, 2021; 53: 103050. doi: 10.1016 / j.msard.2021.1103050. Online ahead of print.
BACKGROUND: The few observational studies that have examined the long-term effects of interferon beta and glatiramer acetate have generally focused on progression to irreversible disability and other outcomes such as the number of relapses and the transition to secondary progressive multiple sclerosis (PMSS). studied. The objective of this article is to estimate the effect of interferon-beta / glatiramer acetate on the progression to irreversible disability, the transition from relapsing-remitting multiple sclerosis (RRMS) to SPMS and the relapse rate. over 10 years.
METHODS: Analyzes included 2498 patients with a confirmed diagnosis of RRMS followed in Montreal from 1977 to 2016. Marginal structural models with a treatment propensity score and censorship were used to account for confounding and dementia factors. ‘potential attrition. Specifically, we used pooled logistic regression for progression to irreversible disability and transition to PMSC, and Poisson models for relapse rate.
RESULTS: 77% of subjects were female and the median age at diagnosis of RRMS was 35 years. The risk of progression to irreversible disability was lower in treated patients than in untreated patients (HR = 0.73, 95% CI [0.57-0.94]). We found no evidence of an association between beta interferon / glatiramer acetate and the rate of transition to SPMS, either over 3-month intervals or during the course of treatment. Patients treated for> 5 years had a lower relapse rate than untreated patients (HR = 0.70, 95% CI [0.57-0.86]).
Conclusion: Beta interferon / glatiramer acetate therapy suggests a beneficial effect on progression to irreversible disability and relapse rate, but not on transition to SPMS.