Incidence of multiple sclerosis in the general population in the Netherlands, 1996-2008

Neuroepidemiology. 2012;39(2):96-102. doi: 10.1159/000338678. Epub 2012 Jul 17.

Abstract

Background: We estimated the multiple sclerosis (MS) incidence in the Netherlands for better active monitoring of potential vaccine safety signals.

Methods: A retrospective cohort study (1996-2008) was conducted using a population-based general practice research database containing electronic medical records. Additional information was collected to validate incident probable cases.

Results: In the source population (648,656 persons), 146 incident probable MS cases were identified. Overall incidence rate was 6.3/100,000 person years (py; 95% CI, 5.2-7.2). In the subgroup in which MS could be fully validated, the incidence increased from 4/100,000 py (95% CI, 3-5) in 1996-2004 to 9/100,000 py in 2007/8 (95% CI, 6-16). This increase was highest among women, but not statistically significantly different by gender. The median lag time between first recorded symptoms and MS diagnosis decreased from 32 months (<1998) to 2 months (>2005).

Conclusions: MS is rare in the Netherlands. In recent years, there was a slight increase in the incidence especially among women during the fertile age. This increase coincided with a decrease in lag time between symptoms and diagnosis, both for men and women. This trend should be taken into account in the interpretation of MS cases occurring in a population where new vaccinations will be introduced shortly.

MeSH terms

  • Adolescent
  • Adult
  • Age Distribution
  • Aged
  • Cohort Studies
  • Databases, Factual
  • Female
  • Humans
  • Incidence
  • Male
  • Middle Aged
  • Multiple Sclerosis / epidemiology*
  • Netherlands / epidemiology
  • Retrospective Studies
  • Sex Distribution