Beta-interferon exposure and onset of secondary progressive multiple sclerosis
Background and purpose Beta‐interferons (IFNβ) are the most widely prescribed drugs for patients with multiple sclerosis (MS). However, whether or not treatment with IFNβ can delay secondary progressive MS (SPMS) onset remains unknown. Our aim was to examine the association between IFNβ exposure and...
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Published in | European journal of neurology Vol. 22; no. 6; pp. 990 - 1000 |
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Main Authors | , , , , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
England
Blackwell Publishing Ltd
01.06.2015
John Wiley & Sons, Inc John Wiley and Sons Inc |
Subjects | |
Online Access | Get full text |
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Summary: | Background and purpose
Beta‐interferons (IFNβ) are the most widely prescribed drugs for patients with multiple sclerosis (MS). However, whether or not treatment with IFNβ can delay secondary progressive MS (SPMS) onset remains unknown. Our aim was to examine the association between IFNβ exposure and SPMS onset in patients with relapsing−remitting MS (RRMS).
Methods
A retrospective cohort study using British Columbia (Canada) population‐based clinical and health administrative data (1985–2008) was conducted. RRMS patients treated with IFNβ (n = 794) were compared with untreated contemporary (n = 933) and historical (n = 837) controls. Cohort entry was the first clinic visit during which patients became eligible for IFNβ treatment (baseline). The outcome was time from baseline to SPMS onset. Cox regression models with IFNβ as a time‐dependent exposure were adjusted for sex, and baseline age, disease duration, disability, *socioeconomic status and *comorbidities (*available for the contemporary cohorts only). Additional analyses included propensity score adjustment.
Results
The median follow‐up for the IFNβ‐treated, untreated contemporary and historical controls were 5.7, 3.7 and 7.3 years, and the proportions of patients reaching SPMS were 9.2%, 11.8% and 32.9%, respectively. After adjustment for confounders, IFNβ exposure was not associated with the risk of reaching SPMS when either the contemporary or the historical untreated cohorts were considered (hazard ratio 1.07; 95% confidence interval 0.93–1.48, and hazard ratio 1.04; 95% confidence interval 0.74–1.46, respectively). Further adjustments and the propensity score yielded results consistent with the main analysis.
Conclusions
Amongst patients with RRMS, use of IFNβ was not associated with a delayed onset of SPMS. |
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Bibliography: | CIHR - No. MOP-93646 ArticleID:ENE12698 Multiple Sclerosis Society of Canada istex:F90BF30809F6A251B08242A0C51828CE1273A1D3 Data S1. Supplementary analyses. Figure S1. Time-dependent Cox regression analysis of potential factors associated with time to SPMSa onset for IFNβ-treated versus the contemporary untreated cohortb (with additional adjustment of SES and high impact/prevalence comorbidities). Figure S2. Selection of the study population from the British Columbia Multiple Sclerosis clinic database: patients with relapsing-onset MS with symptom onset between 1975 and 1995. Figure S3. Survival curves of time from MS symptom onset to SPMS occurrence within 10 years' disease duration, by 5-year onset intervals. Table S1. Multivariable Cox regression analysis of potential factors affecting time to reach SPMS within 10 years from disease onset. ark:/67375/WNG-B9T31299-K NMSS - No. RG 4202-A-2 ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 1351-5101 1468-1331 1468-1331 |
DOI: | 10.1111/ene.12698 |