Table 6. Multivariate analysis using linear regression analysis for the factors associated with SDS.

			95 % Confidence Interval
Parameter	P value	Ratio of the speed	Lower Bound	Upper Bound
M-loop vs. non-traction	0.001	1.46	1.15	1.70
Age (per 1-year increase)	0.021	0.99	0.98	1.00
Male vs. Female	0.037	1.21	1.01	1.45
Right vs. Left	0.529	1.06	0.89	1.27
Area (per 2 times increase)	< 0.001	1.36	1.23	1.50
Elevated vs. Flat	0.651	1.06	0.83	1.35
Fibrosis (per 1-category increase)	0.015	0.78	0.65	0.95
Expert vs. Non-expert	< 0.001	1.85	1.50	2.27