Influence of Socio-Economic Factor on Net Survival in Patients With Multiple Sclerosis in France ( ECOVIMUS).

Study Overview
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Brief Summary
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Background: In comparison to general population, persons with Multiple Sclerosis have a higher risk to premature death with an estimate reduced life expectancy from 7 to 14 years. However, risk factors of mortality in MS are not well identified and well known. Following the example of studies carry on cancers survival, socioeconomic status (SES) may have an influence on survival in MS. Objective: The main objective of ECOVIMUS is to estimate net survival according to SES using the European Deprivation Index as a proxy and other major covariates (gender, initial clinical phase and years of disease onset). Methods: In order to answer to our main objective, we will use a retrospective cohort of MS patients with a medical follow-up in one of the 18 centers included in SURVIMUS II, with a MS onset between 1960 and 2015 and with an informed vital at the date of December 31st, 2015. The ecological score of deprivation EDI will be used as a proxy of the socioeconomic status and will be attributed from the geolocalisation to patient's residence address. Net survival is directly associated to the notion of mortality in excess. This mortality will be estimated comparing the observed mortality in MS patients to mortality in the general population. The advantage of this methodological approach is that cause of death is not needed. Statistical analysis: The influence of socioeconomic status on the excess of mortality will be estimated thanks to a parametric multivariate model of excess rate mortality. This model will be adjusted on other major covariates (gender, age at disease onset, and initial clinical phase) and will include potential complex effects as non-linearity, non-proportionality and interactions. Expected results: We expect to highlight some differences of net survival in MS patients according to socioeconomic group as it was already shown in cancers. This study will complete information on factors of mortality excess in MS and knowledge on socioeconomic inequalities encountered all along MS disease course.

Official Title
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Influence of Socio-Economic Factor on Net Survival in Patients With Multiple Sclerosis in France ( ECOVIMUS).

Conditions
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C10.114.375.500

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: all patients registered in 17 selected French OFSEP centres with core dataset with a sufficient level of data Diagnosis a of definite or probably MS according to Poser or McDonald criteria. With an MS onset date between January 1st, 1960 and December 31st, 2015. With a postal residence address well informed in the OFSEP database. Exclusion Criteria: MS patients with less than one year's disease duration by the study end will be excluded.

Ages Eligible for Study
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Minimum Age: 1 Year
Maximum Age: 100 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Excess mortality survival | Net survival is defined as the probability of death in a hypothetical setting where the cause of interest (in our case MS) would be the only possible cause of death. It is directly linked to the concept of the excess mortality due to the studied disease. Net survival can be calculated according to two settings, either the estimator of survival can be calculated from death due to MS while cause of death are known, either it can be calculated from the excess of mortality due to MS compared to the mortality of the general population obtained from mortality table of the generable population. | From date of MS onset to the date of patients death or to study cut-off date on 1st January 2016. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| European Deprivation Index (EDI) proxy of Socio-Economic Status | The EDI Score is a combination of weighted ecological variates and is available for each 'IRIS area' (Ilots regroupés pour l'Information Statistique). An IRIS area represents the smallest geographical entity for which census data are available in France. The geolocation of each individual address, according to latitude and longitude coordinates, is performed with the system of geographical information (SGI) ARGIS® 10.5. This point of geolocation is correlated to the IRIS area and then an EDI score can be attributed to patients registered in the database. The EDI score can be categorized into quintiles. | From date of MS onset to the date of patients death or to study cut-off date on 1st January 2016. | 
| Distance to MS expert care center | Distance in kilometer by road transport from residence place to MS expert care center | From date of MS onset to the date of patients death or to study cut-off date on 1st January 2016. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Multiple Sclerosis, Epidemiology, Socio-Economic Status, Net Survival