It is interesting that this study differs so much from the 2012 Italian study (not referenced), which found in a similarly large sample size that "DMDs significantly reduce the risk of multiple sclerosis progression" and that "the risk of secondary progression was significantly lower in patients treated with DMDs." (Link: http://www.ncbi.nlm.nih.gov/pubmed/22653657). One reason may be the length of the two studies. The below JAMA study looked at 4/5 years of data; the Italian study looked at at least 10+ years. Perhaps both studies are correct; say disability is not that different in the first five years (on or off interferon), but over time, DMDs more heavily influence disease progression. Or maybe it's time to more seriously consider interferon alternatives like Tysabri, Gilenya and Copaxone. - Dave
Association Between Use of Interferon Beta and Progression of Disability in Patients With Relapsing-Remitting Multiple Sclerosis
Afsaneh Shirani, MD; Yinshan Zhao, PhD; Mohammad Ehsanul Karim, MSc; Charity Evans, PhD; Elaine Kingwell, PhD; Mia L. van der Kop, MSc; Joel Oger, MD, FRCPC; Paul Gustafson, PhD; John Petkau, PhD; Helen Tremlett, PhD
[+] Author Affiliations
JAMA. 2012;308(3):247-256. doi:10.1001/jama.2012.7625 Text Size: A A A
Article
Figures
Tables
References
ABSTRACT
Interferon beta is widely prescribed to treat multiple sclerosis (MS); however, its relationship with disability progression has yet to be established.
Objective To investigate the association between interferon beta exposure and disability progression in patients with relapsing-remitting MS.
Design, Setting, and Patients Retrospective cohort study based on prospectively collected data (1985-2008) from British Columbia, Canada. Patients with relapsing-remitting MS treated with interferon beta (n = 868) were compared with untreated contemporary (n = 829) and historical (n = 959) cohorts.
Main Outcome Measures The main outcome measure was time from interferon beta treatment eligibility (baseline) to a confirmed and sustained score of 6 (requiring a cane to walk 100 m; confirmed at >150 days with no measurable improvement) on the Expanded Disability Status Scale (EDSS) (range, 0-10, with higher scores indicating higher disability). A multivariable Cox regression model with interferon beta treatment included as a time-varying covariate was used to assess the hazard of disease progression associated with interferon beta treatment. Analyses also included propensity score adjustment to address confounding by indication.
Results The median active follow-up times (first to last EDSS measurement) were as follows: for the interferon beta–treated cohort, 5.1 years (interquartile range [IQR], 3.0-7.0 years); for the contemporary control cohort, 4.0 years (IQR, 2.1-6.4 years); and for the historical control cohort, 10.8 years (IQR, 6.3-14.7 years). The observed outcome rates for reaching a sustained EDSS score of 6 were 10.8%, 5.3%, and 23.1% in the 3 cohorts, respectively. After adjustment for potential baseline confounders (sex, age, disease duration, and EDSS score), exposure to interferon beta was not associated with a statistically significant difference in the hazard of reaching an EDSS score of 6 when either the contemporary control cohort (hazard ratio, 1.30; 95% CI, 0.92-1.83; P = .14) or the historical control cohort (hazard ratio, 0.77; 95% CI, 0.58-1.02; P = .07) were considered. Further adjustment for comorbidities and socioeconomic status, where possible, did not change interpretations, and propensity score adjustment did not substantially change the results.
Conclusion Among patients with relapsing-remitting MS, administration of interferon beta was not associated with a reduction in progression of disability.
Full article: http://jama.jamanetwork.com/article....icleid=1217239
Association Between Use of Interferon Beta and Progression of Disability in Patients With Relapsing-Remitting Multiple Sclerosis
Afsaneh Shirani, MD; Yinshan Zhao, PhD; Mohammad Ehsanul Karim, MSc; Charity Evans, PhD; Elaine Kingwell, PhD; Mia L. van der Kop, MSc; Joel Oger, MD, FRCPC; Paul Gustafson, PhD; John Petkau, PhD; Helen Tremlett, PhD
[+] Author Affiliations
JAMA. 2012;308(3):247-256. doi:10.1001/jama.2012.7625 Text Size: A A A
Article
Figures
Tables
References
ABSTRACT
Interferon beta is widely prescribed to treat multiple sclerosis (MS); however, its relationship with disability progression has yet to be established.
Objective To investigate the association between interferon beta exposure and disability progression in patients with relapsing-remitting MS.
Design, Setting, and Patients Retrospective cohort study based on prospectively collected data (1985-2008) from British Columbia, Canada. Patients with relapsing-remitting MS treated with interferon beta (n = 868) were compared with untreated contemporary (n = 829) and historical (n = 959) cohorts.
Main Outcome Measures The main outcome measure was time from interferon beta treatment eligibility (baseline) to a confirmed and sustained score of 6 (requiring a cane to walk 100 m; confirmed at >150 days with no measurable improvement) on the Expanded Disability Status Scale (EDSS) (range, 0-10, with higher scores indicating higher disability). A multivariable Cox regression model with interferon beta treatment included as a time-varying covariate was used to assess the hazard of disease progression associated with interferon beta treatment. Analyses also included propensity score adjustment to address confounding by indication.
Results The median active follow-up times (first to last EDSS measurement) were as follows: for the interferon beta–treated cohort, 5.1 years (interquartile range [IQR], 3.0-7.0 years); for the contemporary control cohort, 4.0 years (IQR, 2.1-6.4 years); and for the historical control cohort, 10.8 years (IQR, 6.3-14.7 years). The observed outcome rates for reaching a sustained EDSS score of 6 were 10.8%, 5.3%, and 23.1% in the 3 cohorts, respectively. After adjustment for potential baseline confounders (sex, age, disease duration, and EDSS score), exposure to interferon beta was not associated with a statistically significant difference in the hazard of reaching an EDSS score of 6 when either the contemporary control cohort (hazard ratio, 1.30; 95% CI, 0.92-1.83; P = .14) or the historical control cohort (hazard ratio, 0.77; 95% CI, 0.58-1.02; P = .07) were considered. Further adjustment for comorbidities and socioeconomic status, where possible, did not change interpretations, and propensity score adjustment did not substantially change the results.
Conclusion Among patients with relapsing-remitting MS, administration of interferon beta was not associated with a reduction in progression of disability.
Full article: http://jama.jamanetwork.com/article....icleid=1217239
Comment