Table 1

Multivariate associations of a negative diffusion-weighted imaging (DWI) and MRI (T2 or fluid-attenuated inversion recovery (FLAIR) or DWI)

Variable	Negative DWI		Negative MRI (T2/FLAIR/DWI)
Variable	OR (95% CI)	p Value	OR (95% CI)	p Value
Age (years)	0.97 (0.95 to 1.00)	0.047	0.96 (0.93 to 0.98)	0.001
Male sex	0.44 (0.24 to 0.81)	0.008	0.46 (0.24 to 0.87)	0.018
National Institute for Health Stroke Scale score	0.70 (0.54 to 0.91)	0.008	0.76 (0.58 to 1.01)	0.059
Persisting symptoms at time of scan (yes/no)	0.61 (0.29 to 1.28)	0.191	0.50 (0.23 to 1.08)	0.077
Time from stroke to scan (days)	1.02 (1.01 to 1.03)	0.003	1.01 (1.00 to 1.02)	0.132

The odds ratios (ORs) are per unit increase in the explanatory variable, and all ORs are corrected for all explanatory variables in the table.