Table 2.

Baseline demographic information and summary information for performance on the American National Adult Reading Test (ANART; Visit 1) and the two-subtest Wechsler Abbreviated Scale of Intelligence (WASI; Visit 2).

Group		Control	Far	Mid	Near
Total Participants	N	51	135	138	98
Age	M	42.9	37.6†	43.3	45.9
	SD	9.9	8.1	10.2	10.9
	range	27.0–62.6	30.0–58.8	26.6–72.9	26.0–75.9
Education	M	15.1	14.7	14.4	14.5
	SD	2.4	2.6	2.8	2.6
	range	9–20	9–20	8–20	8–20
Gender	% female	62.8	65.4	62.9	57.1
Region of Testing	USA	32	87	84	63
	Canada	9	24	25	19
	Australia	10	24	29	16
ANART number correct	M	33.9	34.2	33.1	32.8
	SD	7.5	6.9	8.6	8.4
	range	18–47	15–48	10–48	9–49
	d	--	.22	.02	−.11
WASI Vocabulary raw score	M	66.7	64.0	63.5	61.2⋄
	SD	7.3	7.9	8.5	9.3
	range	47–80	36–76	32–80	31–76
	d	--	−.25	−.31	−.73
WASI Matrix Reasoning raw score	M	26.8	27.3	25.7	24.7⋄
	SD	3.6	4.4	5.1	5.6
	range	16–34	10–35	6–34	8–34
	d	--	−.05	−.12	−.39
two-subtest WASI Combined raw score	M	93.6	90.7	88.4	86.1⋄
	SD	8.8	10.3	11.9	12.7
	range	67–109	50–109	48–113	47–107
	d	--	−.22	−.30	−.72
ANART Verbal IQ Estimate*	M	100	100	102	103
	range	99–124	96–125	91–125	82–126
WASI Verbal IQ Estimate*	M	114	109	109	103⋄
	range	82–142	69–134	62–142	60–134
WASI Performance IQ Estimate*	M	109	109	106	103⋄
	range	84–137	66–141	57–137	53–137
WASI Full Scale IQ Estimate*	M	113	110	109	103⋄

Note. Far = far from estimated clinical diagnosis (> 15 years); Mid = midway to estimated clinical diagnosis (9–15 years); Near = near to estimated clinical diagnosis (< 9 years); IQ = intelligence quotient. Summary information for WASI scores is based on 404 participants (removing 18 participants who were diagnosed at visit 2). Cohen’s d estimates compare the prodromal HD groups to the control group and are adjusted for age, gender, education, and testing region. IQ estimates (as indicated by *) are conversions of raw scores using the published ANART conversion equation for the ANART, or the conversion tables published in the WASI manual for the WASI estimates.¹

^†indicates that the Far from diagnosis group is significantly younger than any of the other groups (including controls)

^⋄indicates a significant difference between the Near to diagnosis group and controls