Table 1.
Demographic, Cognitive and Driving Characteristics of the Study Sample
| Diagnostic Group | ||||||
|---|---|---|---|---|---|---|
| Variable | Full sample (N = 83) |
Controls (n = 24) |
Alzheimer’s (n = 26) |
Parkinson’s (n = 33) |
Test Statistica |
Group Differencesc |
| Gender | 12.30** | |||||
| Male | 58 (69.9%) | 12 (50%) | 16 (61.5%) | 30 (90.9%) | ||
| Female | 25 (30.1%) | 12 (50%) | 10 (38.5%) | 3 (0.9%) | ||
| Age (yrs) | 72.1 (5.5) | 73.1 (5.1) | 75.2 (5.5) | 72.0 (4.1) | 3.64* | |
| Education (yrs) | 15.7 (3.1) | 16.2 (2.7) | 16.2 (3.2) | 14.9 (3.2) | 1.68 | |
| MMSE score | 28.6 (1.3) | 29.1 (1.3) | 28.5 (1.5) | 28.4 (1.2) | 2.17 | |
| TMT-A | 45.9 (18.3) | 35.5 (8.6) | 53.3 (23.4) | 47.6 (15.6) | 7.06** | c |
| TMT-B | 111.8 (54.0) | 77.3 (18.8) | 134.9 (69.9) | 118.8 (44.6) | 9.07*** | c |
| CFT | 28.0 (4.1) | 29.1 (3.6) | 28.8 (3.9) | 26.5 (4.4) | 3.51* | d |
| BVRT | 6.5 (3.4) | 3.8 (2.0) | 7.7 (3.2) | 7.5 (3.3) | 14.00*** | c |
| BD | 32.0 (11.3) | 37.2 (11.2) | 30.7 (10.5) | 29.0 (10.9) | 4.13* | c |
| Driving errorse | 39.8 (15.0) | 37.3 (13.8) | 40.0 (16.8) | 41.5 (14.4) | 0.57 | |
Note. MMSE = Mini-Mental State Exam; TMT-A = Trail Making Test, Trail A; TMT-B = Trail Making Test, Trail B; CFT = Complex Figure Task Copy; BVRT = Benton Visual Retention Test Errors; BD = Wechsler Adult Intelligence Scale-III Block Design Test. Values reflect means and standard deviations except for gender. Follow-up tests were conducted with Fisher’s protected (or LSD) test.
Differences between study groups are tested by one-way analysis of variance (tests statistic, F), with the exception of gender which is evaluated by chi-square with two degrees of freedom.
Between-group differences on neuropsychological scores were evaluated post hoc with Fisher’s protected (LSD) test.
AD, PD performed worse than NC.
PD performed worse than NC, AD.
Driving errors are as defined by the Iowa Department of Transportation for assessment of driving performance.
p < .10.
p < .05.
p < .01.
p < .001.