Table 1. Sample Characteristics by Site and Subgroup.
| Characteristic | Group, No. (%) | |||
|---|---|---|---|---|
| Canberra (n = 307) | Brisbane (n = 253) | |||
| Comparison (n = 202) | Cognitively impaired (n = 105) | Comparison (n = 129) | Vision impaired (n = 124) | |
| Age, median (IQR), y | 75.0 (71.0 to 80.0) | 77.0 (71.0 to 80.0) | 71.0 (68.0 to 76.0) | 74.0 (70.0 to 78.0) |
| Men | 119 (58.9) | 66 (62.9) | 78 (60.5) | 87 (70.2) |
| Education, median (IQR), y | 16.0 (13.0 to 18.0) | 16.0 (12.0 to 19.0) | 14.0 (12.0 to 17.0) | 14.0 (11.0 to 17.0) |
| MMSE, median (IQR) | 29.0 (28.0 to 30.0) | 29.0 (28.0 to 30.0) | 29.0 (28.0 to 30.0) | 29.0 (28.0 to 30.0) |
| Screening Test score, median (IQR) | ||||
| UFOV, msa | 83.0 (30.0 to 167.0) | 137.0 (40.0 to 280.0) | 97.0 (43.0 to 222.0) | 153.0 (77.0 to 263.0) |
| DriveSafeb | 92.0 (82.0 to 100.0) | 84.0 (73.0 to 96.0) | 94.0 (78.0 to 107.0) | 86.0 (70.0 to 100.0) |
| DriveSafe Intersectionb | 7.0 (6.0 to 7.0) | 6.0 (5.0 to 7.0) | 7 (6.0 to 7.5) | 6.0 (5.0 to 7.0) |
| 14-Item Road Lawb | 32.0 (30.0 to 34.0) | 32.0 (29.0 to 34.0) | 35.0 (33.0 to 36.0) | 35.0 (33.0 to 36.0) |
| Maze test time, sa | 23.9 (17.0 to 32.0) | 28.2 (21.0 to 37.0) | 24 (17.4 to 30.8) | 25.5 (19.7 to 33.3) |
| TMT-B, sa | 96.5 (74.4 to 124.3) | 123.0 (89.0 to 177.8) | 96.7 (83.5 to 131.9) | 111.4 (87.3 to 148.8) |
| HPT response time, sa | 5.5 (4.8 to 6.5) | 6.2 (5.0 to 7.6) | 6.1 (5.2 to 7.0) | 6.2 (5.3 to 7.6) |
| Multi-D, median (IQR) | ||||
| Choice reaction time, sa | 0.9 (0.8 to 1.0) | 0.9 (0.8 to 1.1) | 0.9 (0.8 to 1.0) | 0.9 (0.8 to 1.0) |
| Dot motion (logDegArc)b | −1.8(−2.0 to −1.7) | −1.8 (−1.9 to −1.6) | −1.8 (−1.9 to −1.7) | −1.6 (−1.8 to −1.5) |
| Sway path length, mma | 141.0 (114.0 to 192.0) | 163.5 (120.5 to 235.5) | 121.0 (89.5 to 148.0) | 132.5 (110.0 to 177.5) |
| Vision, median (IQR)a | ||||
| High contrast acuity both eyes, logMAR | 0 (−0.1 to 0.1) | 0 (0 to 0.1) | −0.1 (−0.1 to 0.0) | 0 (−0.1 to 0.1) |
| Contrast sensitivity, logCS | 1.7 (1.7 to 1.7) | 1.7 (1.6 to 1.7) | 1.8 (1.8 to 1.8) | 1.8 (1.7 to 1.8) |
| Unsafe score in on-road test | 18 (8.7) | 13 (10.9) | 9 (7.0) | 25 (20.2) |
| Driving habits | ||||
| Distance/wk, km | ||||
| <50 | 22 (10.9) | 19 (18.1) | 27 (20.9) | 20 (16.1) |
| 51-100 | 35 (17.3) | 27 (25.7) | 29 (22.5) | 35 (28.2) |
| 101-200 | 76 (37.6) | 30 (28.6) | 36 (27.9) | 35 (28.2) |
| >200 | 56 (27.7) | 24 (22.9) | 33 (25.6) | 31 (25.0) |
| Missing | 13 (6.4) | 5 (4.8) | 4 (3.1) | 3 (2.4) |
| Frequency, d/wk | ||||
| <3 | 6 (3.0) | 10 (9.5) | 7 (5.4) | 9 (7.3) |
| 3-4 | 35 (17.3) | 18 (17.1) | 27 (20.9) | 31 (25.0) |
| 5-6 | 75 (37.1) | 35 (33.3) | 51 (39.5) | 44 (35.5) |
| Every day | 80 (39.6) | 40 (38.1 | 41 (31.8) | 40 (32.3) |
| Missing | 6 (3.0) | 2 (1.9) | 3 (2.3) | 0 |
| Motor vehicle collisions | ||||
| Past 12 mo | ||||
| 0 | 171 (84.7) | 83 (79.0) | 115 (89.1) | 112 (90.3) |
| 1 | 20 (9.9) | 18 (17.1) | 13 (10.1) | 12 (9.7) |
| 2 | 2 (1.0) | 0 | 0 | 0 |
| Missing | 9 (4.5) | 4 (3.8) | 1 (0.8) | 0 |
| Past 5 y | ||||
| 0 | 140 (69.3) | 69 (65.7) | 93 (72.1) | 90 (72.6) |
| 1 | 39 (19.3) | 25 (23.8) | 25 (19.4) | 26 (21) |
| 2 | 10 (5.0) | 4 (3.8) | 8 (6.2) | 5 (4) |
| 3 | 2 (1.0) | 3 (2.9) | 2 (1.6) | 2 (1.6) |
| 4 | 0 | 0 | 0 | 1 (0.8) |
| Missing | 11 (5.4) | 4 (3.8) | 1 (0.8) | 0 |
Abbreviations: HPT, Hazard Perception Test; IQR, interquartile range; MMSE, Mini Mental State Examination; TMT-B, Trail Making Test Part B; UFOV, Useful Field of View.
a
Lower values represent better performance.
b
Higher values represent better performance.