Table 1

 Baseline characteristics of patients with systemic lupus erythematosus and controls

VariableNo drugsHydroxychloroquineAzathioprinePrednisoneHealthy controlsp Value
The Kruskal-Wallis test was used to compare all groups for age and duration of disease, Fisher’s exact test was used to compare all groups for sex and for influenza vaccination in the past/last season.
*p = 0.026, patients on azathioprine v other patient groups.
†p<0.001, SLE patients v healthy controls.
Age (years)45 (29 to 78)42 (26 to 66)47 (28 to 64)46.5 (18 to 71)40.5 (21 to 57)0.518
(median (range))
Sex (male/female)4/81/161/120/144/140.068
Duration of disease (years)8 (2 to 43)9 (3 to 45)10 (4 to 29)5 (1 to 36)0.730
(median (range))
Influenza vaccination in8/41/612/12/24/14† <0.001
the past (yes/no)
Influenza vaccination last6/67/1012/1*9/51/17† <0.001
season (yes/no)