TABLE 1.
Sample characteristics
| Characteristic | Overall (N = 99) | Cognitively unimpaired (N = 51) | Cognitively impaired (N = 48) | P |
|---|---|---|---|---|
| Age | 56.38 (0.52) | 56.42 (0.63) | 56.32 (0.86) | .926 |
| Intracranial volume | 1516.23 (15.51) | 1532.05 (18.58) | 1498.72 (25.36) | .292 |
| Cognitive domains | ||||
| Response speed | 0.08 (0.01) | 0.08 (0.01) | 0.07 (0.01) | 8.61E‐05 |
| Processing speed | 0.06 (0.01) | 0.07 (0.00) | 0.06 (0.01) | 2.32E‐04 |
| Episodic memory | 0.64 (0.17) | 0.72 (0.19) | 0.56 (0.10) | 2.68E‐06 |
| Intra‐individual response variability | 0.10 (0.04) | 0.09 (0.03) | 0.12 (0.04) | 2.34E‐05 |
| Visuospatial function | 75.08 (47.36) | 57.08 (15.42) | 95.04 (61.21) | 4.40E‐05 |
| Visuospatial memory | 13.28 (9.09) | 9.47 (4.33) | 17.5 (10.99) | 5.42E‐06 |
| Throughput | 0.32 (0.04) | 0.33 (0.04) | 0.30 (0.03) | 3.74E‐05 |
| Working memory | 0.95 (0.12) | 0.99 (0.12) | 0.91 (0.10) | 3.39E‐04 |
| Posttraumatic stress disorder | ||||
| No | 52.5% | 53.9% | 51.1% | .782 |
| Yes | 47.5% | 46.2% | 48.9% | |
| Posttraumatic stress symptomatology | ||||
| Re‐experiencing | 17.48 (6.73) | 17.16 (7.02) | 17.83 (6.45) | .620 |
| Avoidance | 24.07 (9.54) | 24.18 (10.56) | 23.96 (8.44) | .910 |
| Hyperarousal | 17.76 (6.73) | 17.45 (7.25) | 18.08 (6.21) | .643 |
| Negative experiences | 12.23 (4.59) | 12.41 (4.83) | 12.04 (4.36) | .691 |
| Severe WTC exposure | ||||
| No | 87.4% | 90.2% | 84.1% | .172 |
| Yes | 12.6% | 9.8% | 15.9% | |
| Sex | ||||
| Male | 85.3% | 80.8% | 76.6% | .612 |
| Female | 14.7% | 19.2% | 23.4% | |
| Minority status | ||||
| White | 77.8% | 86.5% | 68.1% | .087 |
| Black | 10.1% | 5.8% | 14.9% | |
| Hispanic | 12.1% | 7.7% | 17.0% | |
| Occupation | ||||
| NYPD | 56.6% | 60.8% | 52.1% | .383 |
| Other | 43.4% | 39.2% | 47.9% | |
| Education | ||||
| High school or less | 23.2% | 17.7% | 29.2% | .359 |
| Some college | 47.5% | 49.0% | 45.8% | |
| University degree | 29.3% | 33.3% | 25.0% |
Note: Means (standard deviations) or percentages (%) reported. P‐values examine the extent to which noted characteristics differ across cognitive status and were derived using χ2 tests for categorical variables, and Student's t‐tests for continuous variables. All significant effects passed the false discovery rate.
Abbreviations: NYPD, New York Police Department; WTC, World Trade Center.