Table 8.

Model for anxiety (cumulative link mixed-effects model) and negative affect (linear mixed-effects model) with variance inflation factor–reduced heart rate variability features derived from beat-to-beat interval data during normal work hours of 8 AM to 6 PM^a.

Predictors	Positive affectb				Negative affectc				Anxietyd
	Standardized β	Standardized 95% CI	P value	IRRe		95% CI	P value	ORf (95% CI)		P value
Intercept	−.01	−0.07 to 0.05	<.001	6.32		6.22 to 6.43	<.001	—g		—
MRRIh	−.15	−0.17 to −0.12	<.001	0.99		−0.06 to −0.004	.06	0.90 (0.83 to 0.97)		.004 i
LFj/HFk	−.08	−0.10 to −0.07	<.001	1.00		−0.03 to 0.01	.88	0.92 (0.87 to 0.97)		.002 i
VLFl	.12	0.09 to 0.15	<.001	1.04		0.06 to 0.12	<.001	1.51 (1.39 to 1.65)		<.001 i
Triangular index	.00	−0.02 to 0.02	.91	0.98		−0.08 to −0.03	.001	0.91 (0.85 to 0.97)		.005 i
SDANNm	−.03	−0.05 to −0.01	.002	0.98		−0.07 to −0.03	<.001	0.76 (0.72 to 0.81)		<.001 i

^aModels fit on 14,695 observations from 657 participants. P values <.05 are highlighted in italics. Cumulative link mixed-effects model thresholds are omitted for brevity. An extended version with threshold values is available in Table S16 in Multimedia Appendix 5.

^bRandom effects: σ²=9.03; τ₀₀=9.69; participant intraclass correlation coefficient 0.52; marginal R²/conditional R²=0.020/0.527.

^cRandom effects: σ²=0.15; τ₀₀=0.03; participant intraclass correlation coefficient 0.19; marginal R²/conditional R²=0.004/0.191.

^dRandom effects: σ²=3.29; τ₀₀=2.51; participant intraclass correlation coefficient 0.43; marginal R²/conditional R²=0.015/0.441.

^eIRR: incidence rate ratio.

^fOR: odds ratio.

^gThe predictor was not included in this model.

^hMRRI: mean RR interval.

ⁱP values lower than .05 are highlighted in italics.

^jLF: low frequency.

^kHF: high frequency.

^lVLF: very low frequency.

^mSDANN: SD of the averages of normal-to-normal intervals.