Estimating Typical Multiple Sclerosis Disability Progression Speed from Clinical Observations

Autor: Pantelis Andreou, Vern Hicks, Murray G. Brown, Sarah Kirby, Thomas J. Murray, Dong Lin, Mark Asbridge
Rok vydání: 2014
Předmět:
Gerontology
Multiple Sclerosis
Epidemiology
Immunology
lcsh:Medicine
Plant Science
Disease Surveillance
Research and Analysis Methods
Natural history of disease
Autoimmune Diseases
Database and Informatics Methods
Disability Evaluation
Mathematical and Statistical Techniques
Medicine and Health Sciences
medicine
Humans
Clinical Epidemiology
Disability progression
lcsh:Science
Brain Diseases
Multidisciplinary
Expanded Disability Status Scale
business.industry
Pharmacoepidemiology
Multiple sclerosis
lcsh:R
Disease progression
Biology and Life Sciences
Neurodegenerative Diseases
Plant Pathology
Research Assessment
medicine.disease
Natural history
Natural History of Disease
Nova Scotia
Neurology
Research Design
Disease Progression
Epidemiological Methods and Statistics
Population study
Clinical Immunology
lcsh:Q
Observational study
Economic Epidemiology
business
Research Article
Demography
Zdroj: PLoS ONE, Vol 9, Iss 10, p e105123 (2014)
PLoS ONE
ISSN: 1932-6203
DOI: 10.1371/journal.pone.0105123
Popis: Introduction Multiple sclerosis (MS) is a chronic disease of the central nervous system. Estimates of MS natural history (NH) disability progression speed from clinical observations vary worldwide. This may reflect, in part, variance in censoring-bias) (missing observations) and assumptions about when irreversible disability progression events occurred. We test whether estimates of progression speed which assume midpoint survival time at irreversible disability endpoints are significantly faster than estimates which assume maximum survival time, and are more stable across study groups and time periods. Methods Our Nova Scotia NH study population includes 2,240 definite relapsing-onset multiple sclerosis (R-MS) natural history patients with 18,078 Expanded Disability Status Scale (EDSS) clinical observations in study period 1979–2010. Progression speed is measured by rate-of-change in range EDSS 0–6 and by survival time at irreversible endpoints EDSS 1–9. Midpoint censoring-bias-reduction methods are applied to clinical observations. Findings Typical EDSS increase per year in range EDSS 0–6, assuming midpoint survival time, is estimated to be 0.168 for all R-MS, 0.204 for eventually-DMD-treated patients and 0.155 for never-DMD-treated patients. Estimates assuming midpoint rather than maximum survival time are significantly faster: 16% faster for all R-MS natural history patients, 6% faster for eventually-DMD-treated patients, and 21% faster for never-DMD-treated patients. The variability of estimates across study groups and time periods decreased when midpoint survival time was assumed. Conclusions Estimates of typical disease progression speed from 1979–2010 Nova Scotia clinical observations are sensitive to censoring-bias and to analysts’ survival time assumptions. Censoring-bias-adjusted estimates of typical natural history disability progression speed in relapsing-onset multiple sclerosis patients are significantly faster, and less variable within and across study groups and time periods, than unadjusted estimates, and are, arguably, more relevant for various stakeholders. The application of censoring-bias-reduction methods to other multiple sclerosis clinical databases may reduce variability in estimates of disability progression speed worldwide.
Databáze: OpenAIRE
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