Contributions
Abstract: 215
Type: Oral
Abstract Category: Clinical aspects of MS - 5 Epidemiology
Objective: To investigate whether the risks of disability milestones have changed over the last decade in multiple sclerosis (MS) patients in Sweden.
Background: Clinicians' experience from practice and findings from different natural history studies suggest that MS is now a more slowly progressing disease than before.
Design and methods: We established a nationwide population-based retrospective cohort of MS patients through Swedish MS registry including 7731 patients with at least two recorded Expanded Disability Status Scale (EDSS) scores. We followed patients from onset date to confirmed EDSS 3.0, 4.0 and EDSS 6.0 between 1995 and 2010. We fitted a Weibull model to evaluate if there has been a significant change in the risk of EDSS 3.0, 4.0 and EDSS 6.0 by calculating hazard ratio (HR) and corresponding confidence interval (CI). This model is equivalent to a Cox model in which the baseline hazard, instead of being nonparametric, is assumed that of a Weibull distribution. Using Weibull models permitted handling the fact that the data are doubly censored.
Results: Adjusting for sex, number of visits, diagnosis delay, and onset age, we found 3% decrease per calendar year of diagnosis for the risk of confirmed EDSS 3.0 (HR=0.97, 95% CI=0.96-0.97), 6% decrease per calendar year of diagnosis for the risk of EDSS 4.0 (HR=0.94, 95% CI=0.93-0.95), and 7% decrease per calendar year of diagnosis for the risk of EDSS 6.0 (HR=0.93, 95% CI=0.92-0.94) for relapsing onset MS. The trends were not significant for patients with progressive onset MS (EDSS 3.0: HR=0.99, 95% CI=0.97-1.02; EDSS 4.0: HR=0.98, 95% CI=0.96-1.01; EDSS 6.0: HR=0.98, 95% CI=0.96-1.00).
Conclusions: Risk of disability milestones decreased significantly over the last decade only in MS patients with relapsing onset MS in Sweden. Our results are compatible with a beneficial effect of MS drugs on progression but may also depend on other factors such as the composition of the patient cohort.
Disclosure:
Omid Beiki: Has received salary from Cognizant Technology Solutions for Epidemiological consulting services for the Pharma companies.
Ali Manouchehrinia: Nothing to disclose.
Paolo Frumento: Nothing to disclose.
Matteo Bottai: Nothing to disclose.
Jan Hillert: Has received honoraria for serving on advisory boards for Biogen, Sanofi-Genzyme and Novartis and speaker's fees from Biogen, Novartis, Merck-Serono, Bayer-Schering, Teva and Sanofi-Genzyme. He has served as P.I. for projects, or received unrestricted research support from, BiogenIdec, Merck-Serono, TEVA, Sanofi-Genzyme and Bayer-Schering. His MS research is funded by the Swedish Research Council and the Swedish Brain foundation.
Abstract: 215
Type: Oral
Abstract Category: Clinical aspects of MS - 5 Epidemiology
Objective: To investigate whether the risks of disability milestones have changed over the last decade in multiple sclerosis (MS) patients in Sweden.
Background: Clinicians' experience from practice and findings from different natural history studies suggest that MS is now a more slowly progressing disease than before.
Design and methods: We established a nationwide population-based retrospective cohort of MS patients through Swedish MS registry including 7731 patients with at least two recorded Expanded Disability Status Scale (EDSS) scores. We followed patients from onset date to confirmed EDSS 3.0, 4.0 and EDSS 6.0 between 1995 and 2010. We fitted a Weibull model to evaluate if there has been a significant change in the risk of EDSS 3.0, 4.0 and EDSS 6.0 by calculating hazard ratio (HR) and corresponding confidence interval (CI). This model is equivalent to a Cox model in which the baseline hazard, instead of being nonparametric, is assumed that of a Weibull distribution. Using Weibull models permitted handling the fact that the data are doubly censored.
Results: Adjusting for sex, number of visits, diagnosis delay, and onset age, we found 3% decrease per calendar year of diagnosis for the risk of confirmed EDSS 3.0 (HR=0.97, 95% CI=0.96-0.97), 6% decrease per calendar year of diagnosis for the risk of EDSS 4.0 (HR=0.94, 95% CI=0.93-0.95), and 7% decrease per calendar year of diagnosis for the risk of EDSS 6.0 (HR=0.93, 95% CI=0.92-0.94) for relapsing onset MS. The trends were not significant for patients with progressive onset MS (EDSS 3.0: HR=0.99, 95% CI=0.97-1.02; EDSS 4.0: HR=0.98, 95% CI=0.96-1.01; EDSS 6.0: HR=0.98, 95% CI=0.96-1.00).
Conclusions: Risk of disability milestones decreased significantly over the last decade only in MS patients with relapsing onset MS in Sweden. Our results are compatible with a beneficial effect of MS drugs on progression but may also depend on other factors such as the composition of the patient cohort.
Disclosure:
Omid Beiki: Has received salary from Cognizant Technology Solutions for Epidemiological consulting services for the Pharma companies.
Ali Manouchehrinia: Nothing to disclose.
Paolo Frumento: Nothing to disclose.
Matteo Bottai: Nothing to disclose.
Jan Hillert: Has received honoraria for serving on advisory boards for Biogen, Sanofi-Genzyme and Novartis and speaker's fees from Biogen, Novartis, Merck-Serono, Bayer-Schering, Teva and Sanofi-Genzyme. He has served as P.I. for projects, or received unrestricted research support from, BiogenIdec, Merck-Serono, TEVA, Sanofi-Genzyme and Bayer-Schering. His MS research is funded by the Swedish Research Council and the Swedish Brain foundation.