Table 2.

Multiple regression analysis between the TIS total score and demographic and other clinical assessments.

	β	VIF	p value
Age	0.01	1.56	0.87
Body height	−0.01	1.58	0.73
Body weight	0.02	1.11	0.58
Duration of disease	0.02	1.08	0.63
Barthel index	0.14	2.75	0.01**
Levodopa equivalent daily dose	0.04	1.06	0.27
MDS-UPDRS II 9 Turning in bed	−0.12	1.36	0.002**
MDS-UPDRS III total score	−0.08	2.75	0.14
Hoehn and Yahr stage	−0.16	2.64	0.003**
Mini-BESTest total score	0.27	4.06	0.00003***
General lower extremity extension torque	0.01	3.18	0.93
Two-minute walk test	0.05	2.60	0.35
Handgrip force	0.07	2.39	0.16

R² = 0.52, p < 0.0001. ^*p < 0.05, ^**p < 0.01. β, standardized partial regression coefficient; VIF, variance inflation factor; R2, multiple coefficient of determination; MDS-UPDRS, movement disorders society-unified Parkinson’s disease rating scale; Mini-BESTest, Mini Balance Evaluation Systems Test; TIS, Trunk Impairment Scale.