Table 3.
Prediction model of time in moderate-to-vigorous physical activity in patients with chronic spinal pain and comorbid insomnia.
| Dependent variable | Independent variable | n | b (95% CI) | Β | Adjusted R² | P | VIF | Unadjusted b (95% CI) |
|---|---|---|---|---|---|---|---|---|
| Final model including control variables | ||||||||
| MVPA | Age# | 59 | -0.1 (-0.18, 0.08) | -0.1 | .414 | 1.3 | -0.1 (-0.23, 0.06) | |
| Sex#a | 59 | 1.7 (-1.18, 4.53) | 0.1 | .245 | 1.2 | 3.3 (0.11, 6.44) | ||
| Level of education# | 59 | 1.2 (-0.67, 2.98) | 0.14 | .210 | 1.0 | 2.0 (-0.14, 4.17) | ||
| BFS – Physical fatigue b | 59 | -0.9 (-1.65, -0.20) | -0.3 | .014 | 1.2 | -0.6 (-1.40, 0.21) | ||
| SF-36 Role emotional functioning c | 59 | 0.1 (0.02, 0.10) | 0.4 | .004 | 1.2 | 0.0 (0.00, 0.09) | ||
| BFS – Mental fatigue b | 59 | -1.0 (-1.63, -0.33) | -0.4 | .004 | 1.4 | -0.6 (-1.26, 0.05) | ||
| PSQI d | 59 | 0.7 (0.17, 1.13) | 0.3 | .009 | 1.3 | 0.3 (-0.20, 0.83) | ||
| BMI | 59 | -0.4 (-0.83, -0.00) | -0.2 | .050 | 1.3 | -0.4 (-0.84, 0.05) | ||
| (Constant) | 25.7 (14.62, 36.85) | <.001 | ||||||
| Predictive model for MVPA = 25.735 - 0.053 × (Age) + 1.675 × (Sex) + 1.154 × (LoE) - 0.925 × (Physical fatigue) + 0.057 × (SF-36 emo. Funct.) - 0.980 × (Mental fatigue) + 0.650 × (PSQI) - 0.417 × (BMI) | 59 | 0.35 | <.001 | |||||
| Final model after stepwise removal of the weakest, non-significant variables | ||||||||
| BFS – Physical fatigue b | 59 | -0.9 (-1.59, 0.15) | -0.3 | .019 | 1.2 | -0.6 (-1.40, 0.21) | ||
| SF-36 Role emotional functioning c | 59 | 0.1 (0.03, 0.10) | 0.4 | <.001 | 1.2 | 0.0 (0.00, 0.09) | ||
| BFS – Mental fatigue b | 59 | -1.0 (-1.67, -0.43) | -0.4 | .001 | 1.3 | -0.6 (-1.26, 0.05) | ||
| PSQI d | 59 | 0.7 (0.22, 1.17) | 0.4 | .005 | 1.3 | 0.3 (-0.20, 0.83) | ||
| BMI | 59 | -0.5 (-0.93, -0.16) | -0.3 | .006 | 1.0 | -0.4 (-0.84, 0.05) | ||
| (Constant) | 29.4 (20.04, 38.80) | <.001 | ||||||
| Predictive model for MVPA = 29.423 - 0.867 × (Physical fatigue) + 0.065 × (SF-36 emo. Funct.) - 1.045 × (Mental fatigue) + 0.697 × (PSQI) -0.546 x (BMI) | 59 | 0.33 | <.001 | |||||
Linear regression modeling including dependent variable, variables to control for, independent variables, number of participants, unstandardized coefficient B values for each variable and 95% confidence interval, standardized coefficient B values, individual p values, model p value, model adjusted R², variance inflation factor, the equation of the final model, and unadjusted coefficient B values for each variable with corresponding 95% confidence interval and p-values.
b, unstandardized coefficient; β, standardized coefficient Beta; BMI, body mass index; BFS, Brugmann Fatigue Scale; CI, confidence interval; MVPA, Moderate-to-vigorous physical activity; SF-36, 36-Item Short Form Survey; VIF, variance inflation factor.
Additional variables taken into account (control variables).
Sex: Male = 0, Female = 1.
Higher scores represent more fatigue.
Higher scores represent better health outcome.
Higher scores represent worse sleep quality.