Table 7.
Model for perceived stress with variance inflation factor–reduced HRVa features derived from beat-to-beat interval data during normal work hours of 8 AM to 6 PMb.
| Predictors | Perceived stress at the time of survey response from HRVc | Perceived stress at the time of survey response from anxiety, positive affect, and negative affectd | Perceived stress at the time of survey response from anxiety, positive affect, negative affect, and HRVe | |||||
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ORf (95% CI) | P value | OR (95% CI) | P value | OR (95% CI) | P value | ||
| MRRIg | 0.95 (0.89-1.02) | .16 | —h | — | 1.01 (0.94-1.09) | .75 | ||
| LFi/HFj | 0.86 (0.82-0.91) | <.001k | — | — | 0.85 (0.81-0.90) | <.001 k | ||
| VLFl | 1.54 (1.42-1.67) | <.001 k | — | — | 1.31 (1.20-1.43) | <.001 k | ||
| Triangular index | 0.88 (0.83-0.94) | <.001 k | — | — | 0.94 (0.88-1.01) | .10 | ||
| SDANNm | 0.74 (0.69-0.78) | <.001 k | — | — | 0.81 (0.76-0.86) | <.001 k | ||
| Anxiety | — | — | 5.38 (5.05-5.73) | <.001 k | 5.30 (4.97-5.64) | <.001 k | ||
| Positive affect | — | — | 0.96 (0.91-1.01) | .11 | 0.94 (0.89-0.99) | .01 | ||
| Negative affect | — | — | 2.52 (2.37-2.68) | <.001 k | 2.53 (2.38-2.69) | <.001 k | ||
aHRV: heart rate variability.
bModel fit on 14,695 observations from 657 participants. Cumulative link mixed-effects model thresholds are omitted for brevity. An extended version with threshold values is available in Table S15 in Multimedia Appendix 5.
cRandom effects: σ2=3.29; τ00=2.25; participant intraclass correlation coefficient 0.41; marginal R2/conditional R2=0.022/0.420; Akaike information criterion 31,602.
dRandom effects: σ2=3.29; τ00=1.48; participant intraclass correlation coefficient 0.31; marginal R2/conditional R2=0.547/0.688; Akaike information criterion 23,709.
eRandom effects: σ2=3.29; τ00=1.52; participant intraclass correlation coefficient 0.32; marginal R2/conditional R2=0.548/0.691; Akaike information criterion 23,561.
fOR: odds ratio.
gMRRI: mean RR interval.
hThe predictor was not included in this model.
iLF: low frequency.
jHF: high frequency.
kP values lower than .05 are highlighted in italics.
lVLF: very low frequency.
mSDANN: SD of the averages of normal-to-normal intervals.