Table 1.

Prediction of daily pain in multilevel analysis

Predictor variables	Parameter estimate	SE	P value
Level 2 (Individual)
Sex (0=F, 1=M)	-0.378	0.395	0.342
Age	-0.012	0.056	0.832
BMI	0.016	0.084	0.849
SR-WBV (5 Hz = 1, 1.5 Hz = 0)	0.558	0.365	0.126
Level 1 (day)
Training today? (1 = yes, 0 = 0)	0.083	0.085	0.327
Day of training period (1-28)	-0.004	0.007	0.569
Day of training period X SR-WBV	-0.023	0.010	0.021
Intercept	2.567	0.258
Variance level 2	0.952	0.221
Variance level 1	2.074	0.086

n = 1204 daily pain ratings reported by 43 participants during 28 d. Parameter estimate is the fixed parameter estimate of unstandardized regression coefficients. SE is the standard error in unstandardized regression coefficients estimation; Significance levels were calculated by t-values (Parameter Estimate/SE) with j-p-1 degrees of freedom, where j is the number of units on level 2 and p is the number of explanatory variables[12]. SE: Standard error; BMI: Body mass index; SR-WBV: Stochastic resonance whole-body vibration training.