Table 1.
Characteristics of the study sample according to baseline PTSD symptoms
| Complete MZ pairs (Within-pair analysis) | ||||
|---|---|---|---|---|
| Characteristics | All (n=227) | No PTSDa (n=91) | PTSDa (n=91) | p valueb |
| Sociodemographics | ||||
| Age (mean) | 61.6 (3.0) | 61.6 (2.9) | 61.6 (2.8) | - |
| Race (white) | 213 (93.8%) | 86 (94.5%) | 86 (94.5%) | - |
| College graduatec (miss.=10) | 56 (25.6%) | 23 (26.4%) | 26 (29.6) | 0.40 |
| Income (≥$50,000)d (miss.=12) | 112 (52.1%) | 50 (57.5%) | 43 (50%) | 0.16 |
| VA health care user ever | 80 (35.2%) | 22 (24.2%) | 38 (41.8 %) | 0.006 |
| VA service-connected disability status (miss.=5)e | 74 (32.6%) | 22 (24.7%) | 39 (43.3 %) | 0.003 |
| Clinical Characteristics | ||||
| Body Mass Index (miss.=4) | 28.6 (5.1) | 28.6 (5.0) | 29.1 (4.6) | 0.27 |
| Current smoking (miss.=2) | 52 (23.1%) | 15 (16.9%) | 19 (20.9%) | 0.32 |
| Depression symptoms (PHQ ≥5.0)(miss.=1) | 35 (15.6%) | 0 | 27 (31.8%) | <0.001 |
| PTSD symptoms (PCL ≥30) | 115 (50.7%) | 0 | 91 (100%) | - |
PTSD= Post-traumatic stress disorder, miss.= missing, VA= Veterans Affairs, PHQ=Patient Health Questionnaire, PCL=PTSD checklist
PTSD symptoms (PCL≥30) vs. no PTSD symptoms at baseline (PCL<30)
From generalized linear models, restricted to complete monozygotic twin pairs (both twins in pair with covariate and PCL data). Statistical comparisons by age and race were not made due to twins within a pair sharing these features; small differences in age within a twin pair occurred due to the timing of when surveys were completed.
Completed college, vocational school, technical school, or graduate/advanced degrees
approximate median household income in the United States at the time of baseline data collection (2011)
having ever received or applied for VA disability compensation, for any health condition