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- Sawcer, Stephen, et al.
(author)
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Genetic risk and a primary role for cell-mediated immune mechanisms in multiple sclerosis
- 2011
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In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 476:7359, s. 214-219
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Journal article (peer-reviewed)abstract
- Multiple sclerosis is a common disease of the central nervous system in which the interplay between inflammatory and neurodegenerative processes typically results in intermittent neurological disturbance followed by progressive accumulation of disability. Epidemiological studies have shown that genetic factors are primarily responsible for the substantially increased frequency of the disease seen in the relatives of affected individuals, and systematic attempts to identify linkage in multiplex families have confirmed that variation within the major histocompatibility complex (MHC) exerts the greatest individual effect on risk. Modestly powered genome-wide association studies (GWAS) have enabled more than 20 additional risk loci to be identified and have shown that multiple variants exerting modest individual effects have a key role in disease susceptibility. Most of the genetic architecture underlying susceptibility to the disease remains to be defined and is anticipated to require the analysis of sample sizes that are beyond the numbers currently available to individual research groups. In a collaborative GWAS involving 9,772 cases of European descent collected by 23 research groups working in 15 different countries, we have replicated almost all of the previously suggested associations and identified at least a further 29 novel susceptibility loci. Within the MHC we have refined the identity of the HLA-DRB1 risk alleles and confirmed that variation in the HLA-A gene underlies the independent protective effect attributable to the class I region. Immunologically relevant genes are significantly overrepresented among those mapping close to the identified loci and particularly implicate T-helper-cell differentiation in the pathogenesis of multiple sclerosis.
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2. |
- Doward, Lynda C., et al.
(author)
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International Development of the Unidimensional Fatigue Impact Scale (U-FIS)
- 2010
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In: Value in Health. - : Elsevier BV. - 1098-3015. ; 13:4, s. 463-468
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Journal article (peer-reviewed)abstract
- Objective: The 22-item Unidimensional Fatigue Impact Scale (U-FIS) provides an index of the impact of fatigue on patients with multiple sclerosis (MS). The objective is to produce eight new language versions of the U-FIS: Canadian-English, Canadian-French, French, German, Italian, Spanish, Swedish, and US-English. Methods: The U-FIS was translated via two translation panels. Cognitive debriefing interviews conducted with patients in each country assessed face and content validity. Scaling and psychometric properties were assessed via survey data with patients in each country completing the U-FIS, Nottingham Health Profile (NHP), and demographic questions. Results: Cognitive debriefing interviews demonstrated U-FIS acceptability. Analysis of postal survey data showed all new language versions to be unidimensional. Reliability was high, with test-retest correlations and internal-consistency coefficients exceeding 0.85. Initial evidence of validity was provided by moderate to high correlations with NHP scales. The U-FIS was able to discriminate between groups based on employment status, perceived MS severity, and general health. Conclusion: The U-FIS is a practical new measure of the impact of fatigue. It was successfully adapted into eight new languages to broaden availability for researchers. Psychometric analyses indicated that the new language versions were unidimensional and reproducible with promising construct validity.
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- McKenna, Stephen P., et al.
(author)
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International Development of the Patient-Reported Outcome Indices for Multiple Sclerosis (PRIMUS)
- 2010
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In: Value in Health. - : Elsevier BV. - 1098-3015. ; 13:8, s. 946-951
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Journal article (peer-reviewed)abstract
- Background: The Patient-Reported Indices for Multiple Sclerosis (PRIMUS) comprises a suite of three scales for assessing symptoms, activity limitations, and quality of life in multiple sclerosis (MS). It was developed in the UK and has been shown to have excellent psychometric properties. This study describes the adaptation of eight language versions for Canadian English, Canadian French, French, German, Italian, Spanish, Swedish, and US English. Methods: The PRIMUS was translated using the dual-panel process. Cognitive debriefing interviews conducted with MS patients assessed face and content validity. Psychometric and scaling properties were assessed via a two-administration postal survey conducted in each country involving the PRIMUS, the Nottingham Health Profile (NHP), the Unidimensional Fatigue Impact Scale (U-FIS), and demographic questions. Results: Cognitive debriefing interviews demonstrated the acceptability of the new language versions. Analysis of survey data showed that the new language versions of the three PRIMUS scales were unidimensional (as indicated by fit to the Rasch model) and that they had good internal consistency and reproducibility. PRIMUS scale scores correlated as expected with those on the NHP and the U-FIS. The scales in all countries were able to discriminate between groups of patients on the basis of their self-reported MS severity, general health, and employment status. Conclusions: The PRIMUS was successfully adapted into eight new languages. Most of the tests showed the PRIMUS to have good unidimensionality and to have good internal consistency, reproducibility, and construct validity. The measure is now available for use in clinical studies and trials involving these countries and the UK. Further work is required to assess the measure's responsiveness.
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