Table 2.

Multiple linear regression models showing the association between Timed Up & Go delta time (dependent variable) and serum 25OHD concentrations (independent variable) adjusted for clinical characteristics (n = 359)

	Full adjusted model			Backward model
	ß	95 % CI	P value	ß	95 % CI	P value
Serum 25OHD concentration	−0.408	[−0.707; −0.108]	0.008	−0.415	[−0.710; −0.121]	0.006
Age	−0.177	[−0.869; 0.514]	0.604	–	–	–
Female	0.128	[−10.042; 10.297]	0.980	–	–	–
Number of drugs daily taken	−0.305	[−1.646; 1.036]	0.655	–	–	–
Use of psychoactive drugsa	0.542	[−8.926; 10.010]	0.910	–	–	–
Body mass index (kg/m2)	0.757	[0.052; 1.461]	0.035	0.795	[0.127; 1.463]	0.020
Visual acuityf (/10)	0.730	[−0.608; 2.069]	0.284	–	–	–
Lower limb proprioceptione (/8)	−2.407	[−4.677; −0.136]	0.038	–	–	–
Handgrip strengthd (N/m2)	−0.225	[−0.680; 0.230]	0.331
Depression symptomsb	0.543	[−6.655; 7.741]	0.882	–	–	–
Cognitive impairmentc	9.512	[3.083; 15.942]	0.004	9.755	[3.592;15.918]	0.002

Calculated from the following formula: "[ (Performed Timed "Up & Go" − Imagined Timed "Up & Go") / ((Performed Timed "Up & Go" + Imagined Timed "Up & Go") / 2)] × 100. Coefficient of regression ß and significant P value (i.e., P < 0.05) indicated in italics

β Coefficient of regression beta corresponding to an increase or a decrease of delta time, CI confident interval, 25OHD 25-hydroxyvitamin D

^aUse of benzodiazepines or antidepressants or neuroleptics

^bFour-item Geriatric Depression Scale score >1

^cParticipants with impaired Clock drawing test

^dMean value of maximal isometric voluntary contraction strength measured with computerized dynamometers expressed in Newton per square meter

^eMean value from left and right sides, based on graduated tuning fork placed on the lower limb

^fBinocular visual acuity at a distance of 5 m with a Snellen letter test chart