TABLE 1.
Clinical and demographic characteristics of Huntington disease participants by education
| ISCED 0–2 | ISCED 3 | ISCED 4–6 | Global | |
|---|---|---|---|---|
| (N = 1115) | (N = 1491) | (N = 1931) | P‐value* | |
| Men/Women, n (%)/n (%) | 536 (48.1)A/579 (51.9) | 719 (48.2)A/772 (51.8) | 987 (51.1)A/944 (48.9) | 0.144 |
| Region, n (%) | ||||
| Europe | 1051 (94.3)A | 979 (65.7)B | 889 (46.0)C | |
|
North America Australasia Latin America |
42 (3.8)A 14 (1.3)A 8 (0.7)A |
455 (30.5)B 49 (3.3)B 8 (0.5)A |
954 (49.4)C 77 (4.0)B 11 (0.6)A |
<0.001 |
| Age at baseline visit, years (SD) | 54.7A (12.9) | 52.5B (12.0) | 53.6C (11.8) | 0.156 |
| CAG repeat number, number (SD) | 43.9AB (3.6) | 44.0A (3.4) | 43.6B (3.2) | 0.185 |
|
Age at HD diagnosis, years (SD) [sample size] |
50.0A (12.7) [n = 1097] |
48.0B (12.1) [n = 1459] |
49.0C (11.7) [n = 1880] |
0.048 |
| Duration of disease, years (SD) a | 4.9A (4.3) | 4.5B (4.3) | 4.7AB (4.4) | 0.006 |
| Age of onset of motor symptoms, years (SD) | 47.0A (12.1) | 45.4A (11.5) | 46.4A (11.1) | 0.167 |
|
Age of onset of depression, years (SD) [sample size] |
44.6A (13.5) [n = 734] |
42.8B (13.2) [n = 1023] |
42.5B (13.5) [n = 1284] |
0.011 |
|
Age of onset of irritability, years (SD) [sample size] |
46.9A (13.4) [n = 726] |
44.7B (13.1) [n = 921] |
45.0B (12.6) [n = 1147] |
0.001 |
|
Age of onset of cognitive impairment, years (SD) [sample size] |
49.0A (13.2) [n = 649] |
47.4B (11.7) [n = 866] |
47.9AB (11.4) [n = 1144] |
0.009 |
|
UHDRS motor score, median [IQR] [sample size] |
40.0A [26, 58] [n = 1105] |
37.0B [24.0, 54.0] [n = 1486] |
33.0C [20.0, 48.0] [n = 1919] |
<0.001 |
|
UHDRS total functional capacity score, median [IQR] [sample size] |
7.0A [4.0, 10.0] [n = 1065] |
8.0B [5.0, 11.0] [n = 1490] |
9.0C [6.0, 11.0] [n = 1928] |
<0.001 |
|
UHDRS function assessment score, median [IQR] [sample size] |
16.0A [10.0, 21.0] [n = 1065] |
20.0B [14.0, 23.0] [n = 1443] |
21.0C [16.0, 24.0] [n = 1906] |
<0.001 |
|
MMSE score, median [IQR] [sample size] |
24.0A [20.0, 27.0] [n = 618] |
26.0B [23.0, 28.0] [n = 917] |
27.0C [25.0, 29.0] [n = 1197] |
<0.001 |
|
SDMT, median raw score [IQR] [sample size] |
16.0A [8.0, 23.0] [n = 1002] |
21.0B [13.0, 30.0] [n = 1380] |
25.0C [18.0, 34.0] [n = 1823] |
<0.001 |
|
Verbal fluency test, median raw score [IQR] [sample size] |
9.0A [6.0, 13.0] [n = 1072] |
11.0B [8.0, 15.0] [n = 1453] |
12.0C [9.0, 17.0] [n = 1891] |
<0.001 |
|
Stroop color naming test score, median raw score [IQR] [sample size] |
33.0A [22.0, 44.0] [n = 1056] |
40.0B [29.0, 52.0] [n = 1430] |
45.0C [33.0, 56.0] [n = 1871] |
<0.001 |
|
Stroop word reading test, median raw score [IQR] [sample size] |
45.0A [29.0, 60.0] [n = 1046] |
53.0B [38.0, 69.0] [n = 1426] |
59.0C [45.0, 75.0] [n = 1869] |
<0.001 |
| Antipsychotic medication use, n (%) b | 394A (35.3) | 432B (29.0) | 427C (22.1) | 0.001 |
| Vesicular Monoamine Transporter 2 Inhibitor use, n (%) | 204A (18.3) | 241A(16.2) | 261B (13.5) | 0.002 |
| Antipsychotic or VMAT2 Inhibitor use, n (%) | 532A (47.7) | 604B(40.5) | 641C (33.2) | 0.001 |
Duration of disease = age at study baseline – age of HD diagnosis.
Excludes use of quetiapine, clozapine, and pimavanserin.
Global P‐value is the P‐value for the tests for no association between the variable of interest and the ISCED category (eg Sex vs. ISCED). Variable of interest, pairwise hypothesis tests between the three different ISCED groups are summarized symbolically in the form of matched superscripts. ISCED groups which have any superscripts in common (eg A vs. A or A vs. AB) indicate that the pairwise hypothesis test was non‐significant at the P ≤ 0.05 significance level.
Abbreviations: HD, Huntington disease; IQR, interquartile range; ISCED, International Standard Classification of Education; MMSE, Mini‐Mental State Exam; SD, standard deviation; SDMT, Symbol Digit Modalities Test; UHDRS, Unified Huntington Disease Rating Scale.