Table 1.
Sample characteristics at baseline for the eligible sample and stratified by incident mild cognitive impairment status
| Responder characteristics | Total (N = 1800) |
Cognitively intact∗ (N = 1545) |
Mild cognitive impairment at follow-up (N = 255) |
P |
|---|---|---|---|---|
| Mean (SD) | Mean (SD) | Mean (SD) | ||
| Age, years | 53.15 (7.89) | 52.91 (7.68) | 54.59 (8.92) | .001 |
| PTSD symptom severity | 0.13 (0.18) | 0.13 (0.17) | 0.17 (0.23) | <.001 |
| High WTC exposure, % | 10.06 | 9.39 | 14.12 | .038 |
| High WTC exposure and APOE-ε4 carriers, % | 2.22 | 1.49 | 6.67 | <.001 |
| APOE-ε4 carrier versus noncarrier, % | 21.28 | 20.84 | 23.92 | .258 |
| Female versus male, % | 8.50 | 8.35 | 9.41 | .591 |
| Race/ethnicity, % | ||||
| White | 65.96 | 67.51 | 56.48 | |
| Black | 3.94 | 3.37 | 7.45 | <.001 |
| Other | 22.94 | 22.39 | 26.27 | .036 |
| Hispanic | 7.17 | 6.73 | 9.80 | .017 |
| Nontraditional responder | 42.61 | 41.29 | 50.59 | .006 |
| Educational attainment, % | ||||
| High school or less | 49.00 | 48.54 | 51.76 | |
| Some college | 29.89 | 29.32 | 33.33 | .838 |
| University degree | 21.11 | 22.14 | 14.90 | .046 |
| Hypertension | 29.39 | 28.74 | 33.33 | .134 |
| Diabetes | 10.11 | 10.36 | 8.63 | .405 |
| Cardioarterial disease | 4.50 | 4.40 | 5.10 | .612 |
| All-cause cancer | 16.39 | 15.86 | 19.61 | .128 |
| Head injury, % | ||||
| None | 62.67 | 62.72 | 62.35 | |
| Minor | 8.33 | 8.28 | 8.63 | .844 |
| Concussion | 4.33 | 4.53 | 3.14 | .356 |
| Loss of consciousness | 10.11 | 10.10 | 10.20 | .938 |
| Multiple | 14.56 | 14.37 | 15.69 | .617 |
Abbreviations: PTSD, posttraumatic stress disorder; WTC, World Trade Center; SD, standard deviation.
NOTE. Race/ethnicity categories are mutually exclusive; the other race category includes other races and non-Hispanic multirace categories. P values derived from two-tailed t-tests derived from bivariate log-binomial regression.
∗
Responders who were cognitively intact at baseline and remained that way at follow-up.