Multivariate model* assessing the dose-effect relation between exposure to corticosteroids during the month before the index date and occurrence of severe infection.

*Adjusted for gender, mucosal or internal bleeding at diagnosis, lung disease, kidney disease, cardiac disease, diabetes mellitus, exposure to rituximab in the six months before index date, to azathioprine, mycophenolate, cyclosporine and polyvalent immunoglobulin in the month before index date, splenectomy before index date, as well as cumulative exposure to corticosteroids during the five months preceding the month before the index date. Age and disease duration until index date were neutralized by matching. Akaike criteria: 340.154.†Index date: date of infection for cases.Abbreviations: 95% CI: 95% confidence interval; OR: odds ratio.Multivariate model* assessing the dose-effect relation between exposure to corticosteroids during the month before the index date and occurrence of severe infection.