Epidemiology 2 Silvia Romano , Carlo Caltagirone , and Ugo Nocentini
نویسندگان
چکیده
MS has been described in various populations and geographical regions with different frequencies. Generally, the most commonly used frequencies in epidemiological studies of diseases are prevalence and incidence. As described in the next subsection (etiopathogenesis), regional differences in MS prevalence and incidence have contributed to formulating a hypothesis on its pathogenesis. Prevalence is traditionally defined as ameasurement of the proportion of “events” in a population at a given point of time. “Event” is defined as the occurrence of any phenomenon that can be discretely characterized, for example: infection, presence of antibodies, pregnancy. In epidemiology, diseases or infections are the most commonly used events, and therefore prevalence can be defined as the proportion of people in a population (of a state, region, province) that, at any given time, are affected by the disease. Incidence, on the other hand, measures the number of new cases of a disease occurring during a given period (for example, in a month or a year) and identifies the risk (i.e. probability) of developing the disease in the considered population. Since incidence indicates a change in a quantity (new people affected) comparedwith the change in another quantity (time), it is considered to be a dynamic measure. Epidemiological studies, as well as other studies, are made difficult by the particular nature of MS. In fact, epidemiological researches aimed at formulating and testing etiopathogenetic hypotheses demand levels of diagnostic accuracy
منابع مشابه
Assessing clinical correlates of self-rated disability in patients with multiple sclerosis
BACKGROUND Multiple sclerosis (MS) is associated with significant impairment. OBJECTIVE The objective of this article is to identify and compare clinical measures that can predict self-rated disability in patients with MS using the World Health Organization Disability Assessment Schedule II (WHODAS-II). METHODS Patients with MS and healthy controls were consecutively recruited at one center...
متن کاملCoefficient D(av) is more sensitive than fractional anisotropy in monitoring progression of irreversible tissue damage in focal nonactive multiple sclerosis lesions.
BACKGROUND AND PURPOSE Persistently hypointense lesions on T1-weighted MR images have been shown to correlate with the amount of axonal damage and clinical disability in multiple sclerosis (MS) patients. The purpose of this study was to investigate whether diffusion coefficient D(av) and fractional anisotropy (FA) are able to detect quantifiable differences among three groups of focal nonactive...
متن کاملMassimiliano Oliveri , Giovanni A . Carlesimo and Carlo Caltagirone Selective deficit of time
Neurology Giacomo Koch, Massimiliano Oliveri, Giovanni A. Carlesimo and Carlo Caltagirone Selective deficit of time perception in a patient with right prefrontal cortex lesion This information is current as of January 3, 2010 http://www.neurology.org/cgi/content/full/59/10/1658 located on the World Wide Web at: The online version of this article, along with updated information and services, is ...
متن کاملThe role of Glucocorticoid-induced Tumour Necrosis Factor Receptor in developing mouse sympathetic neurons
L. Mckelvey, C. Riccardi, G.W. O’Keeffe. Characterisation of the molecular mechanisms mediating GITR-regulated axonal growth. Neuroscience Ireland 2011, NUI Maynooth, Ireland Laura McKelvey, Humberto Gutierrez, Giuseppe Nocentini, Sean J. Crampton, Carlo R. Riccardi 3 , Gerard W. O’Keeffe. The intracellular portion of GITR enhances NGFpromoted neurite growth through an inverse modulation of Erk...
متن کامل