Table 3.
Variables Selected as Predictors of MCI Incidence and Characteristics at Baseline
| Variable Name | Minimum Value | Maximum value | Mean (Total) | Mean (Converters) | Mean (Stable Normal) | Variable Descriptions |
|---|---|---|---|---|---|---|
| Table 3a. MCI overall | ||||||
| NACCAGEB | 21.00* | 100.00 | 72.43 | 77.32 | 71.48 | Subject age at the initial visit (years) |
| CDRSUM | 0.00 | 6.00 | 0.10 | 0.25 | 0.07 | Standard CDR sum of boxes, 0, 0.5, 1, 1.5, ~18.0 (except scores of 16.5 and 17.5 which are not possible). |
| DECIN | 0.00 | 1.00 | 0.12 | 0.25 | 0.09 | Does the informant report a decline in subject’s memory relative to previously attained abilities? 0 = No, 1 = Yes |
| MOSLOW | 0.00 | 1.00 | 0.17 | 0.20 | 0.15 | Slowness (Has the subject noticeably slowed down in walking or moving or handwriting, other than due to an injury or illness? Has his/her facial expression changed, or become more “wooden” or masked and unexpressive?) 0 = No 1 = Yes |
| MEMORY | 0.00 | 1.00 | 0.05 | 0.11 | 0.03 | Memory in Clinical Dementia Rating (CDR) 0.0 = No impairment 0.5 = Questionable impairment 1.0 = Mild impairment 2.0 = Moderate impairment 3.0 = Severe impairment |
| NACCZLMD | −3.02 | 3.84 | 0.37 | −0.06 | 0.45 | Age-, sex-, and education-adjusted z-score for Logical Memory 1A-Delayed total |
| NACCZTRB | −5.40 | 2.43 | −0.17 | −0.55 | −0.10 | Age-, sex-, and education-adjusted z-score for the Trail B score |
| NACCZVEG | −2.96 | 6.11 | 0.95 | 0.54 | 1.02 | Age-, sex-, and education-adjusted z-score for Category Fluency: vegetables |
| SPEECH | 0.00 | 8.00 | 0.09 | 0.16 | 0.06 | 0 = Normal. 1 = Slight loss of expression, diction and/or volume. 2 = Monotone, slurred but understandable; moderately impaired. 3 = Marked impairment, |
| TAXES | 0,1,2,3,8 | 0 : 90.07%, 1 : 2.18%, 2 : 1.27%, 3 : 0.67%, 8 : 5.80% | 0 : 80.84%, 1 : 5.30%, 2 : 3.91%, 3 : 2.14%, 8 : 7.81% | 0 : 91.84%, 1 : 1.59%, 2 : 0.77%, 3 : 0.39%, 8 : 5.41% | Taxes in Functional Activities Questionnaire (FAQ) In the past four weeks, did the subject have any difficulty or need help with assembling tax records, business affairs, or other papers. 0 = Normal 1 = Has difficulty, but does by self 2 = Requires assistance 3 = Dependent 8 = Not applicable (e.g., never did) |
|
| NACCZLMI | −3.37 | 3.44 | 0.33 | −0.04 | 0.40 | Age-, sex-, and education-adjusted z-score for Logical Memory 1A-Immediate total number of items recalled |
| NACCZWAI | −4.67 | 5.50 | 0.37 | 0.01 | 0.43 | Age-, sex-, and education-adjusted z-score for the WAIS-R Digit Symbol score |
| NACCLEVB | 0.00 | 18.00 | 0.47 | 0.91 | 0.38 | Levy B score for levodopa-nonresponsive symptoms |
| BILLS | 0,1,2,3,8 | 0 : 93.14%, 1 : 1.84%, 2 : 0.67%, 3 : 0.51%, 8 : 3.84% | 0 : 86.14%, 1 : 5.02%, 2 : 2.14%, 3 : 1.95%, 8 : 4.74% | 0 : 94.48%, 1 : 1.23%, 2 : 0.39%, 3 : 0.23%, 8 : 3.67% | Bills in Functional Activities Questionnaire (FAQ) In the past four weeks, did the subject have any difficulty or need help with writing checks, paying bills, or balancing a checkbook. 0 = Normal 1 = Has difficulty, but does by self 2 = Requires assistance 3 = Dependent 8 = Not applicable (e.g., never did) |
|
| NACCZANI | −3.85 | 5.76 | −0.01 | −0.31 | 0.05 | Age-, sex-, and education-adjusted z-score for Category Fluency: animals |
| Table 3b. aMCI | ||||||
| NACCAGEB | 21.00 | 100.00 | 72.23 | 77.96 | 71.48 | Subject age at the initial visit (years) |
| NACCZLMD | −3.02 | 3.84 | 0.38 | −0.12 | 0.45 | Age-, sex-, and education-adjusted z-score for Logical Memory 1A-Delayed total |
| NACCZLMI | −3.37 | 3.44 | 0.34 | −0.08 | 0.40 | Age-, sex-, and education-adjusted z-score for Logical Memory 1A-Immediate total number of items recalled |
| NACCZVEG | −2.96 | 6.11 | 0.97 | 0.56 | 1.02 | Age-, sex-, and education-adjusted z-score for Category Fluency: vegetables |
| MEMORY | 0.00 | 1.00 | 0.04 | 0.10 | 0.03 | Memory in Clinical Dementia Rating (CDR) 0.0 = No impairment 0.5 = Questionable impairment 1.0 = Mild impairment 2.0 = Moderate impairment 3.0 = Severe impairment |
| NACCZWAI | −4.67 | 5.50 | 0.39 | 0.06 | 0.43 | Age-, sex-, and education-adjusted z-score for the WAIS-R Digit Symbol score |
| DECIN | 0.00 | 1.00 | 0.11 | 0.23 | 0.09 | Does the informant report a decline in subject’s memory relative to previously attained abilities? 0 = No, 1 = Yes |
| NACCLEVB | 0.00 | 18.00 | 0.44 | 0.88 | 0.38 | Levy B score for levodopa-nonresponsive symptoms UDS subjects: The Unified Parkinson’s Disease Rating Scale (UPDRS) items can be categorized into two groups: symptoms associated with dopaminergic deficiency and symptoms not associated with dopaminergic deficiency. The Levy B score is a summary score for the severity of UPDRS items not associated with dopaminergic deficiency: speech and axial impairment. Speech (SPEECH)/Arising from a chair (ARISING)/Posture (POSTURE)/gait (GAIT)/Posture stability (POSSTAB) Possible score range: 0 −20 |
| CDRSUM | 0.00 | 6.00 | 0.08 | 0.22 | 0.07 | Standard CDR sum of boxes, 0, 0.5, 1, 1.5, ~18.0 (except scores of 16.5 and 17.5 which are not possible). |
| DECCLIN | 0.00 | 1.00 | 0.04 | 0.10 | 0.03 | Based on the clinician’s judgment, is the subject currently experiencing meaningful impairment in cognition? 0 = No, 1 = Yes |
| COGSTAT | 1.00 | 4.00 | 1.68 | 1.95 | 1.64 | Based on the UDS neuropsychological examination, the subject’s cognitive status is deemed 1 = Better than normal for age 2 = Normal for age 3 = One or two test scores abnormal 4 = Three or more scores are abnormal or lower than expected |
| NACCZTRB | −5.40 | 2.43 | −0.14 | −0.48 | −0.10 | Age-, sex-, and education-adjusted z-score for the Trail B score |
| NACCZANI | −3.85 | 5.76 | 0.01 | −0.28 | 0.05 | Age-, sex-, and education-adjusted z-score for Category Fluency: animals |
| TRAVEL | 0,1,2,3,8 | 0 : 96.07%, 1 : 2.16%, 2 : 0.68%, 3 : 0.35%, 8 : 0.74% | 0 : 90.10%, 1 : 5.58%, 2 : 2.09%, 3 : 0.98%, 8 : 1.26% | 0 : 96.83%, 1 : 1.73%, 2 : 0.50%, 3 : 0.27%, 8 : 0.68% | In the past four weeks, did the subject have any difficulty or need help with traveling out of the neighborhood, driving, or arranging to take public transportation. 0 = Normal 1 = Has difficulty, but does by self 2 = Requires assistance 3 = Dependent 8 = Not applicable (e.g., never did) |
|
| NACCMND | 0.00 | 1.00 | 0.00 | 0.00 | 0.00 | Motor neuron disease write-in on Form D1 0 = No write-in of motor neuron disease or ALS 1 = Write-in indicating presence of motor neuron disease or ALS This variable is designed to flag subjects for whom a clinical diagnosis of “motor neuron disease” (including “ALS” or similar indicative text), was written-in on Form D1. This variable flags the presence of a write-in only, and not whether the condition was considered to contribute to cognitive impairment. |
| Table 3c. naMCI | ||||||
| COGSTAT | 1.00 | 4.00 | 1.66 | 2.07 | 1.64 | Based on the UDS neuropsychological examination, the subject’s cognitive status is deemed: 1 = Better than normal for age 2 = Normal for age 3 = One or two test scores abnormal 4 = Three or more scores are abnormal or lower than expected |
| NACCZWAI | −4.67 | 5.22 | 0.41 | −0.14 | 0.43 | Age-, sex-, and education-adjusted z-score for the WAIS-R Digit Symbol score |
| CDRSUM | 0.00 | 5.00 | 0.08 | 0.30 | 0.07 | Standard CDR sum of boxes, 0, 0.5, 1, 1.5, ~18.0 (except scores of 16.5 and 17.5 which are not possible). |
| MOSLOW | 0.00 | 1.00 | 0.16 | 0.18 | 0.15 | Slowness (Has the subject noticeably slowed down in walking or moving or handwriting, other than due to an injury or illness? Has his/her facial expression changed, or become more “wooden” or masked and unexpressive?) 0 = No 1 = Yes |
| NACCZDBL | −4.24 | 2.51 | 0.07 | −0.26 | 0.09 | Age-, sex-, and education-adjusted z-score for Digit Span Backward length |
| MEMORY | 0.00 | 1.00 | 0.04 | 0.15 | 0.03 | Memory in Clinical Dementia Rating (CDR) 0.0 = No impairment 0.5 = Questionable impairment 1.0 = Mild impairment 2.0 = Moderate impairment 3.0 = Severe impairment |
| NACCZBOS | −9.76 | 1.88 | −0.31 | −0.69 | −0.30 | Age-, sex-, and education-adjusted z-score for the Boston Naming Test score |
| NACCZVEG | −2.96 | 6.11 | 1.00 | 0.53 | 1.02 | Age-, sex-, and education-adjusted z-score for Category Fluency: vegetables |
| DECIN | 0.00 | 1.00 | 0.10 | 0.28 | 0.09 | Does the informant report a decline in subject’s memory relative to previously attained abilities? 0 = No 1 = Yes |
| MOFALLS | 0.00 | 1.00 | 0.06 | 0.05 | 0.06 | Does the subject fall more than usual? 0 = No 1 = Yes |
| NACCZANI | −3.85 | 5.76 | 0.03 | −0.42 | 0.05 | Age-, sex-, and education-adjusted z-score for Category Fluency: animals |
| NACCZTRB | −5.40 | 2.43 | −0.12 | −0.69 | −0.10 | Age-, sex-, and education-adjusted z-score for the Trail B score |
| PRESTAT | 1.00 | 3.00 | 2.08 | 2.03 | 2.08 | Presumed disease status at enrollment. 1 = Case/patient/proband 2 = Control/normal 3 = No presumed disease status |
| MOTREM | 0.00 | 1.00 | 0.13 | 0.13 | 0.13 | Has the subject had rhythmic shaking, especially in the hands, arms, legs, head, mouth or tongue?) 0 = No 1 = Yes |
| JUDGMENT | 0.00 | 1.00 | 0.02 | 0.06 | 0.01 | Judgment & problem solving in CDR 0.0 = No impairment 0.5 = Questionable impairment 1.0 = Mild impairment 2.0 = Moderate impairment 3.0 = Severe impairment |
If response is categorical with multiple responses, we created multiple dummy variables with the lowest category as a reference group. Other variables were treated as continuous variables in all models.
*
: Seven subjects of MCI were under age 50.