Table 3:

Linear mixed-effects models for ADL prediction by PPT

Independent variable	B-coefficient	95% CI (low)	95% CI (high)	p
Baseline
PPT score	−0.08	−0.18	0.03	0.140
PPT impairment	2.18	1.08	3.28	< 0.001
Time-varying
PPT score	−0.13	−0.20	−0.06	< 0.001
PPT impairment	0.74	0.33	1.16	< 0.001

Linear models were constructed with ADL score (UPDRS part II; higher is worse) as the outcome variable. PPT impairment was defined as a score ≤ 10^th percentile. Baseline models measured the effect of baseline PPT on ADL over time and baseline values were also used for all other adjusting covariables. For the time-varying models, the values at each follow-up assessment were used for all covariables. Baseline ADL score was used to adjust all models. B-coefficients (unstandardized) and 95% confidence intervals (95% CI) correspond to the relationship between bimanual PPT score (independent variable) and ADL score. Covariables adjusted for in all models include sex, education (years), age, disease duration, UPDRS III subsections (rigidity, postural tremor, postural instability, hand movements), and Hoehn & Yahr stage.