Table 1.
Sociodemographic and clinical characteristics of twins in the University of Washington Twin Registry.
| Characteristic | Total Sample1 (N=8,544, 100%) n (%) | Males (n=3,413, 39.9%) n (%) | Females (n=5,131, 60.1%) n (%) | p-value2 |
|---|---|---|---|---|
| Mean Age, years (SD) | 32.4 (15.7) | 32.1(15.8) | 32.6 (15.6) | .199 |
| Race | ||||
| White | 7306 (86.0) | 2924 (86.2) | 4382 (85.8) | 0.70 |
| Non-white | 1911 (14.0) | 200 (13.8) | 723 (14.2) | |
| Married or Partnered | ||||
| Yes | 3389 (39.8) | 1234 (36.4) | 2155 (42.1) | <0.001 |
| No | 5118 (60.2) | 2160 (63.6) | 2958 (57.9) | |
| Education Level | ||||
| K-12 | 3186 (37.5) | 1430 (42.2) | 1756 (34.4) | <0.001 |
| College + | 5309 (62.5) | 1957 (57.3) | 3352 (65.6) | |
| CFS | ||||
| Yes | 175 (2.1) | 39 (1.2) | 136 (2.7) | <0.001 |
| No | 8265 (97.9) | 3327 (98.8) | 4938 (97.3) | |
| PTSD | ||||
| Yes | 318 (3.8) | 85 (2.5) | 233 (4.6) | <0.001 |
| No | 8118 (96.2) | 3281 (97.5) | 4837 (95.4) | |
| IES Score | ||||
| ≥ 26 | 2402 (29.9) | 751 (23.7) | 1651 (34.0) | <0.001 |
| < 26 | 5632 (70.1) | 2420 (76.3) | 3212 (66.0) | |
1
Some variables do not add up to the population total (n = 8,544) because of missing values.
2
P-values, which describe the association between sex and each characteristic, were derived from generalized estimating equations that took into account the relatedness of twin pairs.