Table 2.
Parameter estimates of final model and stability assessment using non-parametric bootstrap analysis
| Parameters | Base Model | Final Model | Non-parametric bootstrap |
|---|---|---|---|
| Estimate (%RSE) | Estimate (%RSE) | Mean(95% CI) | |
| MDS-UPDRS23 Baseline | 30.3 (1.54%) | 29.5 (2.30%) | 29.5 (28.3, 30.8) |
| Age (Centered at 63 years old) | NE | 0.376 (22.20%) | 0.378 (0.199,0.563) |
| Female | NE | −0.0968 (27.70%) | −0.0964 (−0.148, −0.042) |
| Cohort (ICICLE-PD, PPMI Genetic Cohort PD, PPMI Genetic Registry PD) | NE | 0.134 (25.30%) | 0.133 (0.0689,0.203) |
| Any PD medications | NE | 0.112 (40.40%) | 0.111 (0.0217, 0.214) |
| Intrinsic Progression Rate (per month) | 0.00974 (8.39%) | 0.0101 (8.91%) | 0.0102 (0.0085, 0.012) |
| LRRK2 mutation | NE | −0.235 (37.40%) | −0.250 (−0.513, −0.0269) |
| Dispersion factor of Beta Distribution | 37.3 (2.53%) | 39.2 (2.57%) | 39.3 (35, 43.8) |
| Random Effect | |||
| MDS-UPDRS23 Baseline | 0.162 (5.87%) | 0.15 (6.26%) | 0.149 (0.13, 0.168) |
| Intrinsic Progression Rate | 2.67 (19.7%) | 0.000236 (9.66%) | 0.000237 (0.000185, 0.000298) |
| Correlation between Baseline and Intrinsic Progression Rate | 0.111 (40.6%) | 0.001270 (28.8%) | 0.001270 (0.000523, 0.00216) |
Abbreviations: ICICLE = Incidence of Cognitive Impairment in Cohorts with Longitudinal Evaluation, LRRK2 = Leucine-rich repeat kinase 2, MDS-UPDRS23 = Movement Disorder Society-Unified Parkinson's Disease Rating Scale part 2 plus part 3 score, NE = not evaluated, PD = Parkinson’s Disease, PPMI = Parkinson’s Progression Marker Initiative, RSE = relative standard error
Notes: 95% CI = 95% confidence interval of parameter estimate based on bootstrap results. Baseline and the typical progression rate in MDS-UPDRS23 score can be estimated as follows: MDS-UPDRS23 Baseline = 29.5*[(1 + 0.134) if Other Cohort-PD]*[(1–0.0968) if Female]]*[(1+0.112) if Any PD medication]* ((AGE/63)0.376). Intrinsic Progression Rate = 0.0101*[(1–0.235) if LRRK2 mutation]. The typical progression rate in MDS-UPDRS23 score was estimated to be dScore/dt=r*Score*(1-Score/max(Score)) = 29.5*0.0101*(1-[29.5/118]), which was approximately 0.22 point/per months.