Age and sex specific incidence rates. Age and sex specific IR is shown in cases per million person years. An increasing frequency of disease with age is seen in all populations. However, only 5 out of 14 shown a bimodal distribution in IR with the peak in younger women not observed in the remaining 9 studies.
Carr et al. BMC Neurology 2010 10:46 doi:10.1186/1471-2377-10-46