Table 1.

Participant characteristics. Values are number (%) unless otherwise indicated.

CharacteristicPatients, n = 198Controls, n = 299p
Age yrs, mean ± SD [range]39 ± 14 [15–76]41 ± 14 [16–75]0.087
0.9312
Male19 (9.6)28 (9.4)
Female179 (90.4)271 (90.6)
< 0.0001
African-American and other minorities126 (63.6)97 (32.4)
White72 (36.4)202 (67.6)
College graduate0.009
  Yes47 (23.7)104 (34.8)
  No151 (76.3)195 (65.2)
Education0.003
  Did not complete high school36 (18.2)26 (8.7)
  Completed high school49 (24.8)63 (21.0)
  Some college66 (33.3)106 (35.5)
  Completed college47 (23.7)104 (34.8)
Clinical features
  Arthritis143 (73.7)
  Pleuritis76 (39.6)
  Pericarditis26 (13.5)
  Seizures/Psychosis12 (6.2)
  Thrombocytopenia22 (11.4)
  Lupus nephritis47 (24.2)
  Anti-dsDNA antibodies50 (26.7)
  • Number of missing data: 5 for arthritis, 7 for pleuritis, 6 for pericarditis, 6 for seizures/psychosis, 6 for thrombocytopenia, 5 for lupus nephritis, and 12 for anti-dsDNA antibodies. Reasons for missing data were lack of permission for use of medical record data for the clinical failures data and non-participation in the blood sample collection for the anti-dsDNA antibody data.