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. 2018 Nov 20;19:405. doi: 10.1186/s12891-018-2312-3

Table 3.

Estimates, standard error and P value from the linear mixed models for heart rate variability indices showing the main effect of group, domain and the interaction (group × domain) in the crude and adjusted models in DPhacto (n = 568)

Variables Crude model Adjusted model*
Estimate Standard error P Estimate Standard error P
IBI, ms
Group 0.93 0.58
 Pain-free 793.8 13.5 935.3 43.4
 Single-site pain 786.1 9.9 936.6 42.4
 Multisite pain 781.1 6.1 930.6 42.0
Domain < 0.01 < 0.01
 Sleep 294.7 4.4 293.1 4.5
 Leisure 39.5 4.4 37.9 4.5
Interaction 0.36 0.28
 Pain-free at sleep −21.8 10.7 −21.6 11.0
 Pain-free at leisure −12.6 10.6 −11.4 10.9
 Single-site pain at sleep −1.2 8.4 5.5 8.8
 Single-site pain at leisure −1.5 8.3 1.2 8.7
ln SDNN
Group 0.55 0.61
 Pain-free 3.92 0.03 4.92 0.11
 Single-site pain 3.95 0.02 4.95 0.11
 Multisite pain 3.95 0.01 4.94 0.11
Domain 0.20 0.07
 Sleep 0.00 0.01 0.00 0.01
 Leisure −0.01 0.01 −0.01 0.01
Interaction 0.36 0.13
 Pain-free at sleep −0.04 0.03 −0.05 0.03
 Pain-free at leisure 0.00 0.03 0.00 0.03
 Single-site pain at sleep −0.05 0.03 −0.07 0.03
 Single-site pain at leisure −0.01 0.03 −0.01 0.03
ln RMSSD
Group 0.54 0.81
 Pain-free 3.17 0.05 4.32 0.17
 Single-site pain 3.17 0.04 4.31 0.16
 Multisite pain 3.17 0.02 4.30 0.16
Domain < 0.01 < 0.01
 Sleep 0.61 0.01 0.61 0.02
 Leisure 0.07 0.01 0.07 0.02
Interaction 0.16 0.13
 Pain-free at sleep −0.10 0.04 − 0.11 0.04
 Pain-free at leisure −0.04 0.04 −0.04 0.04
 Single-site pain at sleep −0.06 0.03 −0.07 0.03
 Single-site pain at leisure −0.03 0.03 −0.02 0.03
ln LF
Group 0.89 0.86
 Pain-free 6.49 0.09 8.96 0.25
 Single-site pain 6.54 0.06 8.99 0.24
 Multisite pain 6.52 0.04 8.98 0.24
Domain < 0.01 < 0.01
 Sleep −0.06 0.03 −0.06 0.03
 Leisure −0.17 0.03 −0.17 0.03
Interaction 0.64 0.41
 Pain-free at sleep −0.04 0.09 − 0.07 0.09
 Pain-free at leisure 0.01 0.09 0.01 0.09
 Single-site pain at sleep −0.09 0.07 −0.12 0.07
 Single-site pain at leisure 0.00 0.07 0.00 0.07
ln HF
Group 0.50 0.79
 Pain-free 4.94 0.12 7.47 0.35
 Single-site pain 4.92 0.08 7.39 0.34
 Multisite pain 4.96 0.05 7.41 0.34
Domain < 0.01 < 0.01
 Sleep 1.40 0.04 1.39 0.04
 Leisure 0.22 0.04 0.22 0.04
Interaction 0.53 0.37
 Pain-free at sleep −0.17 0.10 −0.20 0.10
 Pain-free at leisure −0.08 0.10 −0.07 0.10
 Single-site pain at sleep −0.07 0.08 −0.08 0.08
 Single-site pain at leisure −0.03 0.07 −0.02 0.08
ln LF/HF
Group 0.51 0.82
 Pain-free 1.66 0.08 1.46 0.22
 Single-site pain 1.75 0.06 1.60 0.22
 Multisite pain 1.69 0.03 1.57 0.21
Domain < 0.01 < 0.01
 Sleep −1.51 0.03 −1.51 0.03
 Leisure −0.26 0.03 −0.26 0.03
Interaction 0.22 0.18
 Pain-free at sleep 0.17 0.08 0.18 0.08
 Pain-free at leisure 0.07 0.08 0.06 0.08
 Single-site pain at sleep −0.02 0.06 −0.04 0.07
 Single-site pain at leisure 0.03 0.06 0.02 0.07

IBI Interbeat intervals, SDNN Standard deviation of RR intervals, ln Natural logarithm, RMSSD Square root of the mean squared differences of successive RR intervals, LF Low-frequency power, HF High-frequency power, LF/HF Sympathovagal balance. *Adjusted for: sex, age, BMI, smoking, moderate to vigorous physical activity at work and leisure, sitting time at work and leisure. Work domain was regarded as the reference