Table 4.

Cognition T-scores by disease stage (known groups analysis)

	Prodromal			Early			Late			F	p	Partial η2
	N	Mean	(SD)	N	Mean	(SD)	N	Mean	(SD)
Neuro-QoL Executive Function	195	59.21	12.38	187	49.70	11.42	103	37.45	9.67	122.87	< .0001	0.34
Neuro-QoL General Concerns	194	50.16	9.76	187	45.17	9.99	103	41.43	10.45	27.84	< .0001	0.10
Symbol Digit Modalities (standardized score)	195	98.86	16.82	188	71.77	21.49	85	50.86	20.11	204.40	< .0001	0.47
Color Naming (number correct)	194	76.71	13.07	190	52.02	15.44	105	33.97	13.56	338.57	< .0001	0.58
Word Reading (number correct)	196	97.47	16.61	191	65.37	19.28	102	43.14	17.49	343.14	< .0001	0.59
Interference (number correct)	194	46.60	15.38	189	28.91	10.03	93	17.78	8.77	198.59	< .0001	0.46
Objective Compositea	191	58.14	5.44	185	47.25	6.11	79	40.26	5.58	323.68	< .0001	0.59
Clinician-rated Compositeb	185	53.27	5.03	173	49.02	8.13	100	44.91	9.52	42.99	< .0001	0.16
Self-rated Compositec	195	54.89	5.57	190	49.56	8.33	98	41.20	9.82	103.54	< .0001	0.30

Note: All scores calculated on a T-metric; general neurological population mean=50 and standard deviation=10. Higher scores represent better cognitive function. In all cases the late-stage HD group indicated more problems than either the early-stage or prodromal group and the early-stage HD group reported more problems than the prodromal group.

^aThe objective composite consisted of scores from Symbol Digit Modalities Test, Color Naming, Word Reading, and Interference

^bThe clinician-rated consisted of scores from PBAs Perseverative Thinking Severity and PBAs Disoriented Behavior Severity scores.

^cThe cognition self-rated composite consisted of scores from WHODAS Scores from Questions “In the last 30 days, how much difficulty did you have in: Learning a new task, for example, learning how to get to a new place?” and “In the last 30 days, how much difficulty did you have in: Concentrating on doing something for ten minutes?”