Table 3.
Regression Results
| Univariate Squared Correlations with Step Count (p-value)* | Full Model Squared Semi-partial Correlations (p-value)* | Final Model Squared Semi-partial Correlations (p-value)* | Direction of Association with Step Count | |
|---|---|---|---|---|
| Demographics/Anthropometrics | ||||
|
| ||||
| Age | 0.09 (0.001) | 0.01 (0.206) | - | |
| BMI | 0.00 (0.586) | - | - | |
| Sex | 0.01 (0.243) | - | - | |
| Education level | 0.06 (0.035) | 0.04 (0.077) | - | |
|
| ||||
| PD Disease Characteristics | ||||
|
| ||||
| Time Since Diagnosis | 0.03 (0.090) | 0.02 (0.061) | 0.03 (0.047) | (-) |
| MDS-UPDRS TD/PIGD Category | 0.02 (0.358) | - | - | |
|
| ||||
| Motor Symptoms | ||||
|
| ||||
| H&Y Score | 0.00 (0.920) | - | - | |
| MDS-UPDRS | ||||
| Motor Experiences (II) | 0.01 (0.415) | - | - | |
| Motor Examination (III) | 0.08 (0.002) | 0.04 (0.017) | 0.04 (0.014) | (-) |
|
| ||||
| Non-Motor Symptoms | ||||
|
| ||||
| MDS-UPDRS | ||||
| Non-Motor Experiences (I) | 0.01 (0.359) | - | - | |
| MFIS | ||||
| MFIS Psychosocial | 0.01 (0.393) | - | - | |
| MFIS Physical | 0.02 (0.116) | - | - | |
| MFIS Cognitive | 0.01 (0.398) | - | - | |
| ESS | 0.03 (0.071) | - | - | |
| PD Sleep Scale Score | 0.00 (0.708) | - | - | |
| Fear/worry of Falling (#9, PDQ-39) | 0.11 (<0.001) | 0.04 (0.015) | 0.05 (0.005) | (-) |
|
| ||||
| Comorbidities | ||||
|
| ||||
| Total number | 0.00 (0.543) | - | - | |
| Osteoarthritis | 0.06 (0.008) | 0.02 (0.117) | - | |
| Cardiovascular Conditions | 0.02 (0.112) | 0.02 (0.071) | 0.02 (0.050) | (+) |
| Pulmonary Conditions | 0.01 (0.427) | - | - | |
|
| ||||
| Cardiorespiratory Fitness | ||||
|
| ||||
| VO2 Peak, ml/min/kg | 0.16 (<0.001) | 0.05 (0.006) | 0.10 | (+) |
Note: BMI: body mass index; H&Y, Hoehn & Yahr; MDS-UPDRS, Movement Disorder Society-Unified Parkinson Disease Rating Scale; TD/PIGD, Tremor Dominant/Postural Instability Gait Disorder; MFIS, Modified Fatigue Impact Scale; ESS, Epworth Sleepiness Scale; PDSS, Parkinson Disease Sleep Scale; PDQ-39, Parkinson Disease Questionnaire; VO2Peak, peak rate of oxygen consumption during graded treadmill test.
*
Variables at p≤0.2 for univariate and sub-group models were considered for the full model. All variables in the full model were considered for the final model at the start. After the running the backward elimination model, only the variables significant at the p ≤0.1 were selected for the final model.