. Author manuscript; available in PMC: 2010 Sep 1.

Published in final edited form as: Int J Psychophysiol. 2009 Mar 10;73(3):212–217. doi: 10.1016/j.ijpsycho.2009.03.002

Table 2.

Repeated measures ANOVA for HRV at rest and in response to stress across visits.

HRV parameters	Source of variance	F	p-value
HRV at rest
1. RMSSD	Visit	0.259	0.611
	Sex	0.517	0.472
	Ethnicity	6.994	0.009
	Visit*sex	1.094	0.296
	Visit*ethnicity	2.205	0.138
	Ethnicity*sex	0.101	0.751
	Visitethnicitysex	1.997	0.158
2. HF	Visit	0.129	0.720
	Sex	0.033	0.855
	Ethnicity	8.422	0.004
	Visit*sex	1.240	0.266
	Visit*ethnicity	1.421	0.234
	Ethnicity*sex	0.008	0.930
	Visitethnicitysex	1.396	0.238

HRV in response to stress
1. Response of RMSSD	Visit	0.409	0.523
	Sex	5.690	0.018
	Ethnicity	0.032	0.858
	Visit*sex	0.000	0.983
	Visit*ethnicity	0.551	0.458
	Ethnicity*sex	0.117	0.732
	Visitethnicitysex	0.604	0.438
2. Response of HF	Visit	0.015	0.902
	Sex	5.450	0.020
	Ethnicity	0.026	0.872
	Visit*sex	0.039	0.844
	Visit*ethnicity	0.152	0.697
	Ethnicity*sex	2.623	0.106
	Visitethnicitysex	0.168	0.682

Age at visit 1 was adjusted for in all the models.

Responses of RMSSD and HF to stress were indexed by the (stress-rest)/rest ratio.

ANOVA= analysis of variance; HRV= heart rate variability; HF= high frequency power; RMSSD= root mean square of successive differences of normal RR intervals.