Contributions
Abstract: P925
Type: Poster
Abstract Category: Clinical aspects of MS - 9 Economic burden
Background: Cognitive dysfunction is present in up to 70% of patients with multiple sclerosis (MS). Various aspects of cognitive function can be detrimentally affected: difficulties with memory, abstract and conceptual reasoning, fluency, planning, visuospatial perception, and reduced speed of information processing. Thus cognitive difficulties are likely to cause problems with employment and an individual's global and social functioning.
Objectives: In this study we aimed at determining whether work disability among MS patients could be predicted by the Symbol Digit Modalities Test (SDMT).
Methods: A longitudinal prospective study was conducted, linking data from the nationwide registers, including the Swedish Multiple Sclerosis Register. MS patients (N=903) who had a clinical visit with SDMT recorded throughout 2006‒2009 were identified. Individual data on work disability, operationalised as annual net days of sickness absence and/or disability pension was retrieved at baseline, after 1-year (T1) and 3-year (T3) follow-up.
Descriptive statistics with means, medians, and proportions presented were used to describe the study population. Incidence rate ratios (IRR) were calculated with general estimating equations using a negative binomial distribution and adjusted for gender, age, educational level, family composition, type of living area, and physical disability.
Results: MS patients were categorised into quartiles according to their SDMT score. At baseline, MS patients in the lowest quartile (SDMT 0‒39) had twice as much work disability as the patients in the highest quartile (SDMT 57‒86); 229.9 and 98.5 mean days per annum, respectively. On average, they were also older (40.1 and 34.3 years, respectively), more disabled (median score of the Expanded Disability Status Scale 4.0 and 2.0, respectively) and displayed the highest proportion of patients with lower education (65.2% and 42.4%, respectively).
The estimated IRRs of work disability for MS patients in the lowest quartile were 1.73 (95% CI 1.42‒2.10) at T1 and 1.68 (95% CI 1.40‒2.02) at T3 when compared to those in the highest quartile.
Conclusion: Cognitive function is to a high extent associated with MS patients' work disability, even after adjusting for other factors. SDMT is a simple and time effective screening instrument for cognitive impairment and could be used as a potential tool to identify MS patients who are at high risk of short and long-term sickness absence or disability pension.
Disclosure:
AK declares that there is no conflict of interest.
VDK has received financial support from Stockholm County Council and Biogen´s Multiple Sclerosis Registries Research Fellowship Program.
PT and EF were funded from an unrestricted research grant from Biogen.
TO has received honoraria for advisory boards and/or lecture fees, as well as unrestricted MS research grants from Biogen, Novartis and Genzyme. His MS research is funded by the Swedish Research Council, Knut and Alice Wallenberg foundation, the AFA foundation and AstraZeneca science for life grant.
KA has received unrestricted research grants from Biogen and from the Swedish Research Council for Working Life, Health and Welfare.
JH received honoraria for serving on advisory boards for Biogen and Novartis and speaker´s fees from Biogen, MerckSerono, BayerSchering, Teva and SanofiGenzyme. He has served as P.I. for projects sponsored by, or received unrestricted research support from Biogen, SanofiGenzyme, MerckSerono, TEVA, Novartis and BayerSchering. His MS research is funded by the Swedish Research Council and the Swedish Brain Foundation.
Abstract: P925
Type: Poster
Abstract Category: Clinical aspects of MS - 9 Economic burden
Background: Cognitive dysfunction is present in up to 70% of patients with multiple sclerosis (MS). Various aspects of cognitive function can be detrimentally affected: difficulties with memory, abstract and conceptual reasoning, fluency, planning, visuospatial perception, and reduced speed of information processing. Thus cognitive difficulties are likely to cause problems with employment and an individual's global and social functioning.
Objectives: In this study we aimed at determining whether work disability among MS patients could be predicted by the Symbol Digit Modalities Test (SDMT).
Methods: A longitudinal prospective study was conducted, linking data from the nationwide registers, including the Swedish Multiple Sclerosis Register. MS patients (N=903) who had a clinical visit with SDMT recorded throughout 2006‒2009 were identified. Individual data on work disability, operationalised as annual net days of sickness absence and/or disability pension was retrieved at baseline, after 1-year (T1) and 3-year (T3) follow-up.
Descriptive statistics with means, medians, and proportions presented were used to describe the study population. Incidence rate ratios (IRR) were calculated with general estimating equations using a negative binomial distribution and adjusted for gender, age, educational level, family composition, type of living area, and physical disability.
Results: MS patients were categorised into quartiles according to their SDMT score. At baseline, MS patients in the lowest quartile (SDMT 0‒39) had twice as much work disability as the patients in the highest quartile (SDMT 57‒86); 229.9 and 98.5 mean days per annum, respectively. On average, they were also older (40.1 and 34.3 years, respectively), more disabled (median score of the Expanded Disability Status Scale 4.0 and 2.0, respectively) and displayed the highest proportion of patients with lower education (65.2% and 42.4%, respectively).
The estimated IRRs of work disability for MS patients in the lowest quartile were 1.73 (95% CI 1.42‒2.10) at T1 and 1.68 (95% CI 1.40‒2.02) at T3 when compared to those in the highest quartile.
Conclusion: Cognitive function is to a high extent associated with MS patients' work disability, even after adjusting for other factors. SDMT is a simple and time effective screening instrument for cognitive impairment and could be used as a potential tool to identify MS patients who are at high risk of short and long-term sickness absence or disability pension.
Disclosure:
AK declares that there is no conflict of interest.
VDK has received financial support from Stockholm County Council and Biogen´s Multiple Sclerosis Registries Research Fellowship Program.
PT and EF were funded from an unrestricted research grant from Biogen.
TO has received honoraria for advisory boards and/or lecture fees, as well as unrestricted MS research grants from Biogen, Novartis and Genzyme. His MS research is funded by the Swedish Research Council, Knut and Alice Wallenberg foundation, the AFA foundation and AstraZeneca science for life grant.
KA has received unrestricted research grants from Biogen and from the Swedish Research Council for Working Life, Health and Welfare.
JH received honoraria for serving on advisory boards for Biogen and Novartis and speaker´s fees from Biogen, MerckSerono, BayerSchering, Teva and SanofiGenzyme. He has served as P.I. for projects sponsored by, or received unrestricted research support from Biogen, SanofiGenzyme, MerckSerono, TEVA, Novartis and BayerSchering. His MS research is funded by the Swedish Research Council and the Swedish Brain Foundation.