Table 3.

Multilevel regression predicting logarithmized root mean square of successive differences (lnRMSSD) before, during, and after intervention for both types of triggers (N=50).

Predictors	lnRMSSD
	Estimate, b (95% CI)	P value
Intercept	3.41 (3.29 to 3.53)	<.001
Metabolic equivalents	–0.22 (–0.23 to –0.21)	<.001
Smoking (no vs yes)	–0.28 (–0.31 to –0.25)	<.001
Trigger (0=random vs 1=AddHRVra)	–0.35 (–0.37 to –0.33)	<.001
Intervention (mindful breathing vs external focus)	–0.02 (–0.04 to 0.00)	.047
Time (before intervention vs during intervention)	0.08 (0.07 to 0.10)	<.001
Time (before intervention vs after intervention)	0.04 (0.03 to 0.06)	<.001
Trigger×intervention	–0.07 (–0.11 to –0.02)	.003
Trigger×time (before intervention vs during intervention)	0.04 (–0.00 to 0.08)	.05
Trigger×time (before intervention vs after intervention)	0.09 (0.06 to 0.12)	<.001
Intervention×time (before intervention vs during intervention)	0.03 (–0.01 to 0.07)	.10
Intervention×time (before intervention vs after intervention)	–0.00 (–0.03 to 0.03)	.93
Trigger×intervention×time (before intervention vs during intervention)	0.10 (0.01 to 0.18)	.03
Trigger×intervention×time (before intervention vs after intervention)	0.04 (–0.02 to 0.10)	.23

^aAddHRVr: additional heart rate variability reductions.