Table 4.

Logistic Regression Model^* of Chronic Neurotoxicity at 12 Months (n=75)

Variable	Comparison	Odds Ratio	(95% CI)	p-value
Treatment Arm	2.5 Gy × 10 vs.	RL
	2.0 Gy × 18 vs.	8.00	(1.29, 49.50)	0.03
	1.5 Gy × 24	4.37	(0.81, 23.60)	0.09
Age	Continuous	1.12	(1.04, 1.21)	0.005
Education Level	≤ High School	2.96	(0.85, 10.29)	0.09
	> High School	RL

^*A backward method was used. The following variables were initially entered into the model: Treatment arm (2.5 Gy × 10 (referent) vs. 2.0 Gy × 18 vs. 1.5 Gy × 18), age (continuous), gender (male (referent) vs. female), education level (≤ high school vs. > high school (referent)), and marital status (married/living as married (referent) vs. single/divorced/widowed). Parameters with a p < 0.1 remained in the model.

CI = Confidence Interval; vs. = versus; RL = Reference Level