In the multivariate analysis , initial rhythm of ventricular fibrillation/ventricular tachycardia ( VF/VT ) and survival with good neurologic outcome were strong predictors of obtaining consent ( odds ratio [ OR ] = 3.15 , 95 % confidence interval [ CI ] = 1.73 to 5.75 ; OR = 7.64 , 95 % CI = 2.28 to 25.63 , respectively ) .