Table 3.

Spearman’s r correlations between 6-month sensor driving summary variables (per day) and global cognitive z-scores; n = 28

	Spearman’s r	p-value
Variable
Mean # of trips per day	0.09	0.65
Day-to-day variability in # of trips	0.00	1.00
Mean distance driven per day (miles)	0.51	<0.01**
Day-to-day variability in distance driven	0.47	0.01*
Mean time driven per day (min)	0.39	0.04*
Day-to-day variability in time driven	0.42	0.03*
Mean first clock start time of driving per day	0.16	0.41
Day-to-day variability in first start time	0.44	0.02*
Mean last clock start time of driving per day	0.15	0.44
Day-to-day variability in last start time	0.20	0.30
% of days at least one trip was taken out of all days monitored	−0.26	0.19
% of driving days ≥20 miles	0.44	0.02*

^*p < 0.05;

^**p < 0.01; p = 0.0042 after adjusting for multiple comparisons.