Fig. 1.

Schematic representation of the model used for confirmatory factor analysis with corresponding loading coefficients from the analysis pooled across sites. Rectangles reflect observed variables; ovals reflect latent variables and circles error terms of the model (ε). Simple arrows and corresponding values reflect the factor paths and loadings of observed variables to the latent variables and of the error terms to the corresponding observed variable; double arrows and corresponding values reflect covariance between latent variables or error terms. Bradykin. = Bradykinesia; Cogwheel. = Cogwheeling; Dys.coord = Dysdiadochokinesia coordination; Dys.speed = Dysdiadochokinesia speed; ε = Error term; FPS = Fist palm side; Extrapyr. = Extrapyramidal; Gait disturb. = Gait disturbance