. Author manuscript; available in PMC: 2017 Apr 1.

Published in final edited form as: Alzheimers Dement. 2015 Nov 6;12(4):399–406. doi: 10.1016/j.jalz.2015.09.008

Table 3.

Anxiety comparisons for co-twin analyses.

	Control M (SD) or N (%)	Case M (SD) or N (%)	t or χ²	p
All discordant twin pairs (63 cases 63 controls)
Baseline STPI score	17.11 (5.77)	21.01 (8.55)	3.00	<0.01
Higher than one standard deviation at any time point	20 (39.5%)	32 (61.5%)	4.72	0.03
Baseline anxiety greater than co-twin	18 (31.6.9%)	39 (68.4%)	15.47	<0.01
Discordant MZ twins (17 cases 17 controls)
STPI score	18.88 (6.56)	21.47 (9.52)	0.92	0.36
Higher than one standard deviation at any time point	6 (42.9%)	8 (57.1%)	0.49	0.49
Baseline anxiety greater than co-twin	6 (42.9%)	8 (57.1%)	0.57	0.45
Discordant DZ twins (46 cases 46 controls)
Baseline STPI score	16.45 (5.38)	20.84 (8.27)	3.01	<0.01
Higher than one standard deviation at any time point	14 (36.8%)	24 (63.2%)	4.48	<0.03
Baseline anxiety greater than co-twin	12 (27.9%)	31 (72.1%)	16.79	<0.01

STPI= state anxiety subscale of the State-Trait Personality Inventory

Control = co-twin without dementia

Case = co-twin who developed dementia