Table 1.
Descriptive statistics
| Continuous Predictors | Non-converters |
Converters |
Selected by |
||||
|---|---|---|---|---|---|---|---|
| Mean | S.D. | Mean | S.D. | EN | RFE % | RFE (>50%) | |
| Age | 73.57 | 6.19 | 76.53 | 6.27 | 22% | ||
| Education (y) | 13.23 | 3.15 | 14.70 | 4.59 | 2% | ||
| Body-Mass Index | 69.27 | 8.35 | 71.47 | 8.17 | 2% | ||
| Modified Clinical Dementia Rating Scale, Memory Sum Score | 1.86 | 1.32 | 2.92 | 1.27 | x | 99% | x |
| Geriatric Depression Scale | 2.28 | 2.27 | 2.17 | 2.82 | 1% | ||
| Right hippocampus atrophy (VRS) | 0.90 | 0.87 | 1.77 | 1.17 | x | 100% | x |
| Left hippocampus atrophy (VRS) | 0.87 | 0.82 | 1.70 | 1.06 | x | 100% | x |
| Right entorhinal cortex atrophy (VRS) | 0.54 | 0.76 | 1.53 | 1.17 | x | 100% | x |
| Left entorhinal cortex atrophy (VRS) | 0.65 | 0.82 | 1.50 | 1.23 | x | 100% | x |
| Right perirhinal cortex atrophy (VRS) | 0.53 | 0.70 | 1.27 | 1.20 | x | 100% | x |
| Left perirhinal cortex atrophy (VRS) | 0.51 | 0.72 | 1.10 | 1.19 | x | 34% | |
| Hopkins Verbal Learning Test Revised, Total Recall | 21.48 | 5.31 | 16.20 | 4.71 | x | 96% | x |
| Hopkins Verbal Learning Test Revised, Delayed Recall | 6.99 | 3.09 | 3.10 | 2.94 | x | 100% | x |
| Digit-Symbol-Coding Score (WAIS-III) | 11.17 | 2.64 | 10.47 | 2.43 | 17% | ||
| Block Design Test, Raw Score (WAIS-III) | 26.77 | 8.54 | 23.67 | 7.33 | 4% | ||
| Semantic Interference Test, Retroactive Total Score | 22.89 | 3.80 | 16.87 | 5.88 | x | 100% | x |
| Semantic Interference Test, Recognition Total Score | 26.43 | 3.94 | 21.03 | 5.75 | x | 100% | x |
| Delayed Visual Reproduction (WMS-IV) | 15.74 | 9.60 | 8.83 | 9.46 | x | 12% | |
| Similarities Test, raw score (WAIS-III) | 16.91 | 5.07 | 16.03 | 5.04 | 3% | ||
| Logical Memory, Immediate Recall Score (WMS-IV) | 10.95 | 3.95 | 6.73 | 3.27 | x | 100% | x |
| Logical Memory, Delayed Recall Score (WMS-IV) | 8.62 | 4.49 | 3.97 | 3.16 | x | 100% | x |
| Trial Making A, Time (s) | 39.89 | 13.99 | 49.63 | 18.67 | 46% | ||
| Trial Making A, Errors | 0.17 | 0.43 | 0.10 | 0.31 | 7% | ||
| Trial Making B, Time (s) | 132.18 | 70.32 | 167.90 | 73.45 | x | 31% | |
| Trial Making B, Errors | 1.68 | 3.65 | 1.90 | 1.81 | x | 63% | x |
| Heart Rate (bpm) | 27.91 | 5.39 | 25.97 | 3.73 | 92% | x | |
| Continuous Predictors | Non-converters |
Converters |
Selected by |
||||
|---|---|---|---|---|---|---|---|
| N | % | N | % | EN | RFE % | RFE (>50%) | |
| Gender | 12% | ||||||
| Male | 41 | 44.09% | 12 | 40.00% | |||
| Female | 52 | 55.91% | 18 | 60.00% | |||
| Clinical Dementia Rating Scale, Global Score | 38% | ||||||
| 0 | 12 | 12.90% | 0 | 0.00% | |||
| 0.5 | 81 | 87.10% | 30 | 100.00% | |||
| Hypercholesterolemia | 1% | ||||||
| No | 34 | 36.56% | 7 | 23.33% | |||
| Yes | 59 | 63.44% | 23 | 76.67% | |||
| Hypertension | 2% | ||||||
| No | 42 | 45.16% | 16 | 53.33% | |||
| Yes | 51 | 54.84% | 14 | 46.67% | |||
| Diabetes | 2% | ||||||
| No | 79 | 84.95% | 26 | 86.67% | |||
| Yes | 14 | 15.05% | 4 | 13.33% | |||
| History of tobacco use | 1% | ||||||
| No | 87 | 93.55% | 29 | 96.67% | |||
| Yes | 6 | 6.45% | 1 | 3.33% | |||
| History of myocardial infarction | 100% | x | |||||
| No | 88 | 94.62% | 5 | 16.67% | |||
| Yes | 26 | 27.96% | 4 | 13.33% | |||
| History of coronary bypass/angioplasty | 41% | ||||||
| No | 80 | 86.02% | 26 | 86.67% | |||
| Yes | 13 | 13.98% | 4 | 13.33% | |||
| History of stroke/TIA | 6% | ||||||
| No | 80 | 86.02% | 25 | 83.33% | |||
| Yes | 13 | 13.98% | 5 | 16.67% | |||
| Diagnosis | x | 100% | x | ||||
| aMCI | 27 | 29.03% | 25 | 83.33% | |||
| non-aMCI | 7 | 7.53% | 2 | 6.67% | |||
| PreMCI-cl | 31 | 33.33% | 1 | 3.33% | |||
| PreMCI-np | 28 | 30.11% | 2 | 6.67% | |||
S.D., standard deviation; EN, Elastic Net; RFE, recursive feature elimination; N, number of subjects; aMCI, amnestic mild cognitive impairment; non-aMCI, non-amnestic mild cognitive impairment; PreMCI-cl, premild cognitive impairment – clinical subtype; PreMCI-np, premild cognitive impairment – neuropsychological subtype; WAIS-III, Wechsler Adult Intelligence Scale – Version 3; WMS-IV, Weschler Memory Scale – Fourth Edition; VRS, Visual Rating Scale; y, years; s, seconds; bpm, beat per minute.