Table 3.

Bivariate linear regression analyses

	HRV-biofeedback (n=15)		Control (n=12)
	Unstandardized B coefficient	p- value	Unstandardized B coefficient	p-value
Demographic factors
Age	0.07	0.35	<0.01	0.89
Gender	1.79	0.16	0.00	1.00
Smoking	0.67	0.32	0.20	0.78
Psychometric characteristics
Craving at baseline	0.02	0.59	-0.01	0.93
Craving post-intervention	0.01	0.79	0.04	0.71
Anxiety at baseline	-0.10	0.93	0.16	0.29
Anxiety post-intervention	-0.03	0.73	0.06	0.79
Depression at baseline	-0.03	0.66	0.03	0.70
Depression post-intervention	-0.08	0.33	>0.01	0.95
Heart rate variability
CVNN at baseline	-0.65	0.17	-1.07	0.16
CVNN post-intervention	-0.54	0.26	-0,79	0.21
HF at baseline	<-0.01	0.26	<-0.01	0.41
HF post-intervention	<-0.01	0.26	<-0.01	0.30
LF at baseline	<-0.01	0.23	<-0.01	0.22
LF post-intervention	0.00	0.79	<-0.01	0.48
TP at baseline	0	0.46	<0.01	0.75
TP post-intervention	<0.01	0.79	<-0.01	0.32

Regression analyses in patients who completed follow-up did not reveal any predictors of abstinence among demographic, psychometric or HRV parameters both in patients who have been treated with HRV-biofeedback and controls. “Craving” refers to the Obsessive Compulsive Drinking Scale score. “Anxiety” and “Depression” refer to scores of subscales Anxiety and Depression from the Symptom Checklist-90

CVNN coefficient of variation of R-R intervals, HF high frequency, LF low frequency, TP total power