Table 1.

Characteristics of the study population.

CharacteristicPrimary Sjögren’s Syndrome, n = 50CTD Group*, n = 300Rheumatoid Arthritis, n = 100Systemic Lupus Erythematosus, n = 100Scleroderma, n = 100
Female, n (%)49 (98)289 (96)93 (93)96 (96)93 (93)
Age, yrs, mean ± SD56.0 ± 1147.8 ± 15†49.4 ± 14††40.4 ± 13†53.5 ± 14
Disease duration, yrs, mean ± SD12.5 ± 1112.7 ± 9.714.2 ± 1012.9 ± 1011.1 ± 8
Immunosuppressant use, n (%)14 (28)207 (69)†99 (99)†77 (77)†31 (31)
Prednisone use, n (%)1 (2)65 (21)†2 (2)44 (44)†19†† (19)

  • ↵* Includes all selected patients with RA, SLE, and scleroderma.

  • ↵† p < 0.001 in comparison with primary SS group.

  • ↵†† p < 0.005 in comparison with primary SS group.