Table 3.
Simple and multiple binary logistic regression analyses assessing which demographics, clinical, and behavioural features distinguished underestimators from non-underestimators; 95% bias corrected and accelerated confidence intervals [95% CI] (1000 bootstrap samples) for the logistic regression coefficients were reported in parentheses
| Variable | Estimate [CI 95%] | Bias | SE | p valueb | OR [CI 95%] |
|---|---|---|---|---|---|
| Simple regression | |||||
| Demographics | |||||
| Age | 0.02 [− 0.03, 0.07] | 0.00 | 0.02 | 0.399 | 1.02 [0.97, 1.07] |
| Education, years | − 0.09 [− 0.22, 0.01] | − 0.00 | 0.06 | 0.101 | 0.90 [0.80, 1.01] |
| Sexa | − 0.43 [− 1.29, 0.50] | 0.04 | 0.45 | 0.342 | 0.64 [0.26, 1.58] |
| Clinical features | |||||
| Age at onset | 0.02 [− 0.02, 0.07] | − 0.00 | 0.02 | 0.379 | 1.02 [0.97, 1.07] |
| Disease duration, years | 0.03 [− 0.13, 0.20] | − 0.00 | 0.08 | 0.691 | 1.03 [0.88, 1.19] |
| UPDRS-III | 0.01 [− 0.02, 0.06] | 0.00 | 0.02 | 0.520 | 1.01 [0.96, 1.06] |
| Hoehn and Yahr stage | 0.80 [− 0.27, 2.49] | 0.40 | 2.74 | 0.222 | 2.22 [0.61, 8.07] |
| LEDD total (mg/day) | 0.00 [− 0.00, 0.00] | 0.00 | 0.00 | 0.496 | 1.00 [0.99, 1.00] |
| LEDDDA (mg/day) | − 0.00 [− 0.00, 0.00] | 0.00 | 0.00 | 0.212 | 0.99 [0.99, 1.00] |
| LEDDL-DOPA (mg/day) | 0.00 [− 0.00, 0.00] | 0.00 | 0.00 | 0.471 | 1.00 [0.99, 1.00] |
| Behavioural measures | |||||
| Fatigue Severity Scale | 0.57 [0.30, 0.93] | 0.02 | 0.15 | < 0.001 | 1.77 [1.32, 2.38] |
| Beck Depression Inventory | 0.15 [0.08, 0.26] | 0.01 | 0.05 | < 0.001 | 1.15 [1.07, 1.24] |
| Parkinson Anxiety Scale | 0.10 [0.05, 0.16] | 0.00 | 0.02 | < 0.001 | 1.10 [1.04, 1.16] |
| Apathy Evaluation Scale | 0.10 [0.03, 0.19] | 0.00 | 0.04 | 0.024 | 1.10 [1.01, 1.20] |
| Parkinson’s disease sleep scale | − 0.01 [− 0.04, 0.00] | − 0.00 | 0.01 | 0.228 | 0.98 [0.96, 1.00] |
| Epworth Sleepiness Scale | 0.05 [− 0.05, 0.18] | 0.00 | 0.06 | 0.327 | 1.05 [0.94, 1.16] |
| Multiple regressionc | |||||
| Fatigue Severity Scale | 0.57 [0.09, 1.44] | 0.05 | 0.35 | 0.008 | 1.77 [1.16, 2.71] |
| Beck Depression Inventory | 0.11 [0.01, 0.32] | 0.01 | 0.07 | 0.035 | 1.12 [1.00, 1.25] |
| Parkinson Anxiety Scale | 0.01 [− 0.08, 0.10] | 0.00 | 0.05 | 0.702 | 1.01 [0.93, 1.09] |
| Apathy Evaluation Scale | − 0.06 [− 0.20, 0.04] | − 0.01 | 0.06 | 0.938 | 0.95 [0.85, 1.02] |
Statistically significant variables are shown in bold
SE standard error, OR odds ratio, CI confidence interval, UPDRS Unified Parkinson’s Disease Rating Scale, LEDD levodopa equivalent daily dose
aCoded as: 0 = male, 1 = female
bp value related to unstandardized beta coefficient using the Wald statistic
cModel χ2 (4) = 33.01, p value < 0.01, R2 = 0.44 (Nagelkerke)