New data identify an increasing sex ratio of multiple sclerosis in Sweden.
Bottom Line: The women-to-men ratio increased from 1.70 for patients born in the 1930s to 2.67 for patients born in the 1980s.When comparing the coverage of SMSreg to the full data set, a significantly higher proportion of women born 1931-1935 compared to men born in the same period were found in SMSreg, resulting in a sampling bias hiding the increasing sex ratio in the full material.The women-to-men ratio in MS has increased in Sweden during the 20(th) century similarly to observations in other western countries.
Affiliation: Karolinska Institutet, The Multiple Sclerosis Research Group, Tomebodavägen 18A:05, Stockholm, Solna, 17177, Sweden Helga.Westerlind@ki.se.Show MeSH
Related in: MedlinePlus
License 1 - License 2 - License 3
Mentions: To assess a measure of statistical significance for the increase of the w/m ratio with time we obtained a beta estimate for the different birth cohorts. The model also included as a covariate the birth cohorts mean age at first occurrence in PAR for the 95% of the patients that had at least one occurrence in PAR, to control for this difference throughout the century. The beta for the birth cohorts indicated an increase of the ratio with 0.11 units per cohort (p-value = 0.004). The decrease for mean age at onset estimate from PAR was also significant with a p-value = 0.01. For comparison against previously published results from Sweden, Canada, and Norway, see Figure 1.
Affiliation: Karolinska Institutet, The Multiple Sclerosis Research Group, Tomebodavägen 18A:05, Stockholm, Solna, 17177, Sweden Helga.Westerlind@ki.se.