Table 1.
Baseline characteristics of systemic lupus erythematosus participants
| All participants, at time 1 (n=682) | Never developed depression (n=516) | Developed depression (n=166) | p-value | |
|---|---|---|---|---|
| Demographic | ||||
| Age, mean (SD) years | 51.0 (13.5) | 50.8 (13.7) | 52.4 (13.1) | 0.20 |
| Married or living with a partner | 400 (59%) | 309 (60%) | 90 (54%) | 0.19 |
| Race/ethnicity | ||||
| White | 414 (61%) | 319 (62%) | 95 (57%) | 0.29 |
| Hispanic | 69 (10%) | 49 (9%) | 20 (12%) | 0.34 |
| African American | 72 (11%) | 49 (9%) | 23 (14%) | 0.11 |
| Asian | 81 (12%) | 61 (12%) | 20 (12%) | 0.94 |
| Other | 46 (7%) | 38 (7%) | 8 (5%) | 0.25 |
| Socioeconomic | ||||
| Living below povertya | 88 (13%) | 57 (11%) | 31 (19%) | 0.01* |
| Household Incomeb | ||||
| < $40,000 | 240 (35%) | 164 (32%) | 76 (46%) | < 0.01* |
| $40,000 to < $80,000 | 184 (27%) | 141 (27%) | 43 (26%) | 0.72 |
| ≥ $80,000 | 220 (32%) | 183 (35%) | 37 (22%) | < 0.01* |
| Educational Attainment | ||||
| College degree (Bachelor’s degree or higher) | 306 (45%) | 247 (48%) | 60 (36%) | 0.01* |
| General Health | ||||
| Current smoker | 41 (6%) | 25 (5%) | 13 (8%) | 0.14 |
| Former smoker | 215 (32%) | 158 (31%) | 60 (36%) | 0.18 |
| Body mass index ≥ 26.8 kg/m2 | 277 (41%) | 206 (40%) | 71 (43%) | 0.52 |
| Body mass index ≥ 30 kg/m2 | 174 (26%) | 123 (24%) | 51 (31%) | 0.08 |
| Depressive symptoms, mean (SD) CES-D score | 9.3 (6.6) | 7.8 (6.1) | 14.2 (5.6) | < 0.01* |
| Physical functioning, mean (SD) SF-36-PF score | 41.2 (12.1) | 43.2 (11.5) | 35.8 (11.7) | < 0.01* |
| SLE Characteristics | ||||
| Disease duration, mean (SD) years | 18.0 (8.9) | 18.2 (9.1) | 18.4 (8.5) | 0.72 |
| Disease activity, mean (SD) SLAQ score | 10.2 (6.7) | 8.9 (6.3) | 13.9 (6.7) | < 0.01* |
| Disease damage, mean (SD) BILD score | 1.9 (2.0) | 1.8 (2.0) | 2.2 (2.1) | 0.03* |
| BILD score=0 | 183 (27%) | 146 (28%) | 37 (22%) | 0.13 |
| BILD score=1 | 190 (28%) | 139 (27%) | 51 (31%) | 0.34 |
| BILD score=2 | 109 (16%) | 92 (18%) | 17 (10%) | 0.02* |
| BILD score ≥ 3 | 199 (29%) | 138 (27%) | 61 (37%) | 0.01* |
*
significant at p < 0.05
a
Missing for 15 individuals: 7 who never developed depression and 8 who did
b
Missing for 38 individuals: 28 who never developed depression and 10 who did
CES-D=Center for Epidemiological Studies Depression Scale (0–60)
SF-36-PF=SF-36 Scale of Physical Functioning (0–100)
SLAQ=Systemic Lupus Activity Questionnaire (0–44)
BILD=Brief Index of Lupus Damage (0–26)
-Column 2 data pertains to the earliest observation in the dataset while Column 3 data pertains to the year before depression developed; therefore, the sums of the Column 2 and 3 values do not always equal the Column 1 value