Table 2.
Vision and Driving Characteristics of Older Drivers According to Frequent Fall Status at Baseline
| Characteristic | All Participants, N = 2,000 |
Frequent Faller, n = 174a |
Infrequent or Nonfaller, n = 1,826 |
P-Value |
|---|---|---|---|---|
| Visual acuity, log of the minimum angle of resolution OUb | ||||
| >0.3, n (%) | 161 (8.1) | 15 (8.6) | 146 (8.0) | .78 |
| ≤0.3, n (%) | 1,837 (91.9) | 159 (91.4) | 1,678 (92.0) | |
| Mean ± SD | 0.05 ≥ 0.14 | 0.07 ± 0.15 | 0.05 ± 0.14 | .22 |
| Contrast sensitivity, OUc | ||||
| ≥1.5, n (%) | 1,867 (93.4) | 154 (88.5) | 1,713 (93.9) | .007 |
| <1.5, n (%) | 132 (6.6) | 20 (11.5) | 112 (6.1) | |
| Mean ± SD | 1.67 ≥ 0.13 | 1.64 ± 0.13 | 1.68 ± 0.13 | <.001 |
| Useful Field of View subtest 2, msc | ||||
| <150, n (%) | 1,125 (56.3) | 77 (44.3) | 1,048 (57.4) | .002 |
| 150–350, n (%) | 653 (32.7) | 68 (39.1) | 585 (32.1) | |
| >350, n (%) | 221 (11.1) | 29 (16.7) | 192 (10.5) | |
| Mean ± SD | 163.4 ≥ 135.9 | 206.9 ± 151.5 | 159.3 ± 133.6 | <.001 |
| Trail-Making Test Part B, minutesd | ||||
| <2.47, n (%) | 1,229 (61.6) | 92 (53.2) | 1,137 (62.4) | .02 |
| ≥2.47, n (%) | 766 (38.4) | 81 (46.8) | 685 (37.6) | |
| Mean ± SD | 2.6 ≥ 1.4 | 2.8 ± 1.6 | 2.5 ± 1.4 | .02 |
| Motor-free visual perception | ||||
| 11, n (%) | 606 (30.3) | 52 (29.9) | 554 (30.3) | .87 |
| 8–10, n (%) | 1,094 (54.7) | 98 (56.3) | 996 (54.5) | |
| <8, n (%) | 300 (15.0) | 24 (13.8) | 276 (15.1) | |
| Mean ± SD | 9.3 ± 1.7 | 9.4 ± 1.6 | 9.3 ± 1.7 | .53 |
| Mileage per year | ||||
| <7,300, n (%) | 966 (49.9) | 94 (56.3) | 872 (49.3) | .04 |
| 7,300–10,999, n (%) | 422 (21.8) | 40 (24.0) | 382 (21.6) | |
| ≥11,000, n (%) | 549 (28.3) | 33 (19.8) | 516 (29.2) | |
| Mean ± SD | 9,527.7 ± 9,420.2 | 8,059.2 ± 5,893.6 | 9,667.6 ± 9,679.0 | .002 |
| Number of MVCs past 1 year | ||||
| 0, n (%) | 1,920 (96.0) | 164 (94.3) | 1,756 (96.2) | .29 |
| 1, n (%) | 79 (4.0) | 10 (5.7) | 69 (3.8) | |
| 2, n (%) | 1 (0.1) | 0 (0.0) | 1 (0.1) | |
| Mean ± SD | 0.0 ± 0.2 | 0.1 ± 0.2 | 0.0 ± 0.2 | .31 |
| Number of at-fault MVCs past 1 | ||||
| 0, n (%) | 1,959 (98.0) | 167 (96.0) | 1,792 (98.1) | .08 |
| 1, n (%) | 41 (2.1) | 7 (4.0) | 34 (1.9) | |
| Mean ± SD | 0.0 ± 0.1 | 0.0 ± 0.2 | 0.0 ± 0.1 | .16 |
MVC = motor vehicle collision; OU = both eyes (oculus uterque); SD = standard deviation.
a
Falling ≥2 times in previous year.
b
N=2 missing data.
c
N=1 missing data.
d
N=5 missing data.