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Anticipation of age at onset in multiple sclerosis: methodologic pitfalls

Alonso Magdalena, Lucia LU ; Romero-Pinel, L.; Moral, E.; Carmona, O.; Gubieras, L.; Ramon, J. M.; Martinez-Yelamos, S. and Arbizu, T. (2010) In Acta Neurologica Scandinavica 121(6). p.426-428
Abstract
Background/aim - There are several reports that claim anticipation in complex or polygenic diseases such as multiple sclerosis (MS), Crohn disease or schizophrenia. The aim of the present study was to assess age at onset of MS during the last 60 years in the region of Costa de Ponent (Barcelona, Spain) showing how apparent changes in age at onset between generations can be an artefact of analysis based on cohorts that have not been followed enough time. Methods - The study comprised 1100 patients diagnosed of MS. The method used to correct for follow-up time bias involves constructing comparison cohorts that had been observed for the same amount of time. To ensure equal follow-up times, we restricted our analysis to patients whose onset... (More)
Background/aim - There are several reports that claim anticipation in complex or polygenic diseases such as multiple sclerosis (MS), Crohn disease or schizophrenia. The aim of the present study was to assess age at onset of MS during the last 60 years in the region of Costa de Ponent (Barcelona, Spain) showing how apparent changes in age at onset between generations can be an artefact of analysis based on cohorts that have not been followed enough time. Methods - The study comprised 1100 patients diagnosed of MS. The method used to correct for follow-up time bias involves constructing comparison cohorts that had been observed for the same amount of time. To ensure equal follow-up times, we restricted our analysis to patients whose onset was by 37 years of age (percentile 75) and were at least 37 years old. We analysed differences in age at onset using log-rank test to compare survival curves estimated by Kaplan-Meier method. Results - Age at onset decreases progressively from older to younger generations. However, when adjustment to equal follow-up time was done, anticipation in age at onset was not found. Conclusion - Anticipation of age at onset is undetectable when adjusted for follow-up time. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
natural history, multiple sclerosis, epidemiology, demyelinating diseases, age at onset, anticipation
in
Acta Neurologica Scandinavica
volume
121
issue
6
pages
426 - 428
publisher
Wiley-Blackwell
external identifiers
  • wos:000277783900011
  • scopus:77952594650
ISSN
1600-0404
DOI
10.1111/j.1600-0404.2009.01273.x
language
English
LU publication?
yes
id
24ddfa63-56ae-4148-b1cb-88be158e1e7d (old id 1617639)
alternative location
http://www.ncbi.nlm.nih.gov/pubmed/20578997?dopt=Abstract
date added to LUP
2010-06-22 11:09:47
date last changed
2018-05-29 10:58:01
@misc{24ddfa63-56ae-4148-b1cb-88be158e1e7d,
  abstract     = {Background/aim - There are several reports that claim anticipation in complex or polygenic diseases such as multiple sclerosis (MS), Crohn disease or schizophrenia. The aim of the present study was to assess age at onset of MS during the last 60 years in the region of Costa de Ponent (Barcelona, Spain) showing how apparent changes in age at onset between generations can be an artefact of analysis based on cohorts that have not been followed enough time. Methods - The study comprised 1100 patients diagnosed of MS. The method used to correct for follow-up time bias involves constructing comparison cohorts that had been observed for the same amount of time. To ensure equal follow-up times, we restricted our analysis to patients whose onset was by 37 years of age (percentile 75) and were at least 37 years old. We analysed differences in age at onset using log-rank test to compare survival curves estimated by Kaplan-Meier method. Results - Age at onset decreases progressively from older to younger generations. However, when adjustment to equal follow-up time was done, anticipation in age at onset was not found. Conclusion - Anticipation of age at onset is undetectable when adjusted for follow-up time.},
  author       = {Alonso Magdalena, Lucia and Romero-Pinel, L. and Moral, E. and Carmona, O. and Gubieras, L. and Ramon, J. M. and Martinez-Yelamos, S. and Arbizu, T.},
  issn         = {1600-0404},
  keyword      = {natural history,multiple sclerosis,epidemiology,demyelinating diseases,age at onset,anticipation},
  language     = {eng},
  number       = {6},
  pages        = {426--428},
  publisher    = {Wiley-Blackwell},
  series       = {Acta Neurologica Scandinavica},
  title        = {Anticipation of age at onset in multiple sclerosis: methodologic pitfalls},
  url          = {http://dx.doi.org/10.1111/j.1600-0404.2009.01273.x},
  volume       = {121},
  year         = {2010},
}