TABLE 2.
Results of linear regression models evaluating effect of education level on Huntington's disease characteristics and clinical features
| Adjusted effect size [95% CI] (P‐value) | ||||
|---|---|---|---|---|
| Model | ISCED 3 – ISCED 0–2 | ISCED 4–6 – ISCED 0–2 | ISCED 4–6 – ISCED 3 | ISCED partial association test P‐value* |
| Model 1: Age of onset of motor symptoms a |
−1.32 [−1.91, −0.073] (P < 0.001) |
−1.15 [−1.71, −0.53] (P < 0.001) |
0.18 [−0.33, 0.69] (P = 0.497) |
<0.001 † |
| Model 2: Age of onset of depression a |
−1.85 [−2.93, −0.77] (P = 0.001) |
−2.90 [−3.93, −1.86] (P < 0.001) |
−1.05 [−1.99, −0.11] (P = 0.029) |
<0.001 † |
| Model 3: Age of onset of cognitive impairment a |
−1.58 [−2.41, −0.74] (P < 0.001) |
−2.04 [−2.83, −1.25] (P < 0.001) |
−0.46 [−1.19, 0.26] (P = 0.211) |
<0.001 † |
| Model 4: Age of onset of irritability a |
−1.66 [−2.68, −0.64] (P = 0.002) |
−2.34 [−3.32, −1.36] (P < 0.001) |
−0.68 [−1.59, 0.23] (P = 0.145) |
<0.001 † |
| Model 5: Age of HD diagnosis a |
−1.62 [−2.24, −1.00] (P < 0.001) |
−1.56 [−2.16, −0.97] (P < 0.001) |
0.06 [−0.49, 0.60] (P = 0.839) |
<0.001 † |
| Model 6a: UHDRS motor score b |
−1.17 [−2.63, 0.29] (P = 0.118) |
−5.35 [−6.74, −3.96] (P < 0.001) |
−4.18 [−5.44, −2.91] (P < 0.001) |
<0.001 † |
| Model 6b: UHDRS motor score c |
−0.62 [−2.03, 0.78] (P = 0.385) |
−3.99 [−5.33, −2.65] (P < 0.001) |
−3.36 [−4.58, −2.14] (P < 0.001) |
<0.001 † |
| Model 7: UHDRS total functional capacity score b |
0.74 [0.48, 1.00] (P < 0.001) |
1.25 [1.00, 1.49] (P < 0.001) |
0.51 [0.28, 0.73] (P < 0.001) |
<0.001 † |
| Model 8: UHDRS functional assessment score b |
1.78 [1.29, 2.27] (P < 0.001) |
2.85 [2.39, 3.30] (P < 0.001) |
1.07 [0.65, 1.48] (P < 0.001) |
<0.001 † |
| Model 9: MMSE score b |
1.47 [1.05, 1.90] (P < 0.001) |
2.77 [2.37, 3.17] (P < 0.001) |
1.30 [0.94, 1.65] (P < 0.001) |
<0.001 † |
| Model 10: SDMT score b |
3.94 [3.02, 4.87] (P < 0.001) |
8.19 [7.32, 9.06] (P < 0.001) |
4.25 [3.46, 5.03] (P < 0.001) |
<0.001 † |
| Model 11: Verbal fluency test score b |
1.38 [0.96, 1.80] (P < 0.001) |
2.56 [2.17, 2.96] (P < 0.001) |
1.18 [0.82, 1.54] (P < 0.001) |
<0.001 † |
| Model 12: Stroop color naming test score b |
5.56 [4.70, 6.92] (P < 0.001) |
10.13 [8.84, 11.42] (P < 0.001) |
4.57 [3.40, 5.75] (P < 0.001) |
<0.001 † |
| Model 13: Stroop word reading test score b |
6.82 [5.12, 8.53] (P < 0.001) |
12.79 [11.18, 14.41] (P < 0.001) |
5.97 [4.50, 7.44] (P < 0.001) |
<0.001 † |
Adjusted by CAG repeats.
Adjusted by age of enrollment and CAG repeats.
Adjusted by age of enrollment, CAG repeats and VMAT2 inhibitor and/or antipsychotic use.
ISCED Partial Association Test P‐value is the P‐value for the null hypothesis test that after concomitant variable adjustment ISCED is not uniquely associated with the outcome variable.
Indicates that the P‐value for the global null hypothesis test that “education level” is not uniquely associated with the regression “dependent variable” after removing for the variance in the “dependent variable” explained by the adjustment variable(s) is less than the Benjamini and Hochberg false discovery error rate (0.05) P‐value threshold that if exceeded would indicate a false positive finding.
Abbreviations: SD, Standard deviation; HD, Huntington disease; ISCED, International standard classification of education; MMSE, Mini‐Mental State Exam; SDMT, Symbol Digit Modalities Test; UHDRS, Unified Huntington disease rating scale. ISCED 0–2 vs. ISCED 3, ISCED 3 ‐ ISCED 0–2; ISCED 0–2 vs. ISCED 4–6, ISCED 4–6 ‐ ISCED 0–2; ISCED 3 vs. ICED 4–6, ICED 4–6 ‐ ISCE 3.