Table 1.
Baseline Characteristics of Study Subjects by Their Participation in Follow-up
| Characteristic Collected at the Baseline Visit (N, %) | Study Subjects Who Who Participated in Follow-up N=436 |
Study Subjects Who Did Not Participate in Follow-up N=3387 |
p-value |
|---|---|---|---|
| Age at baseline in years: mean (median) ± sd | 47.2 (48.0) ± 15.3 | 51.7 (52.0) ± 17.2 | <0.0001 |
| Time between contact in years: mean (median) ± sd | 6.1 (5.0) ± 3.9 | 8.0 (8.0) ± 4.1 | <0.0001 |
| Sex: Female | 365 (83.7%) | 2265 (66.9%) | <0.0001 |
| Race: European American | 323 (73.9%) | 1793 (52.9%) | <0.0001 |
| African American | 64 (14.7%) | 835 (24.7%) | |
| Native American | 21 (4.8%) | 185 (5.5%) | |
| Asian/Pacific Islander | 17 (3.9%) | 101 (3.0%) | |
| Hispanic | 11 (2.5%) | 446 (13.2%) | |
| Unknown | 0 (0.0%) | 27 (0.8%) | |
| Relationship to SLE Proband: | <0.0001 | ||
| First Degree Relative (FDR): | |||
| Sister | 195 (44.7%) | 1119 (33.0%) | |
| Brother | 31 (7.1%) | 521 (15.4%) | |
| Child | 29 (6.6%) | 158 (4.7% ) | |
| Parent | 147 (33.7%) | 1406 (41.5%) | |
| Second Degree Relative (SDR) | |||
| or more distant relative | 34 (7.8%) | 32 (0.9%) | |
| ANA Positive | 226 (51.8%) | 1704 (50.3%) | 0.55 |
| SLE-CSQ Categories at Baselinea: | <0.0001 | ||
| Unlikely SLE | 253 (58.0%) | 2444 (63.9%) | |
| Possible SLE | 45 (10.3%) | 304 (9.0%) | |
| Probable SLE | 138 (31.7%) | 639 (18.9%) | |
| Number of ACR Criteria at Baselineb: | <0.0001 | ||
| 0 | 144 (33.0%) | 3027 (89.4%) | |
| 1 | 154 (35.3%) | 47 (1.4%) | |
| 2 | 97 (22.3%) | 246 (7.2%) | |
| 3 | 41 (9.4%) | 67 (2.0%) | |
ANA, anti-nuclear antibodies; CSQ, Connective Tissue Disease Screening Questionnaire; ACR, American College of Rheumatology.
a
SLE-CSQ categories are based on responses to the SLE portion of the CSQ questionnaire. Twenty-eight questions were grouped into 12 categories. If the person indicated that < 3 categories were true, then a person was classified as unlikely SLE. If three of the 12 categories were marked as true, then the person was classified as possible SLE. If the person indicated that at least four of the 12 categories were true, then the person was classified as probable SLE.
b
Confirmed ACR criteria by medical record.