Table 3.

Univariate & multivariate Cox proportional hazards analysis of first seizure prevalence by use of antiepileptic drug (AED) prophylaxis (or not), controlling for factors influencing seizure rate (population A compared with population B)^c using a time-dependent Cox proportional hazards regression model (see also Figure 2)

AED	HR (hazard ratio)	95% CI	P Value
On first AED	0.9647	0.5153-1.8060	.91
Controlled Factors	HR (hazard ratio)	95% CI	P Value
On first AED	1.0225	0.5410-1.9324	.95
Age at diagnosis	1.0038	0.9772-1.0311	.78
Sex (male)	1.3897	0.7526-2.5660	.29
Gross complete resectiona	0.3719	0.1839-0.7523	.006
Partial resectionb	1.4357	0.6133-3.3606	.40
LGG vs HGG	1.5263	0.3605-6.4625	.57

^aGross complete resection, resection of ≥ 95% of the preoperatively defined contrast-enhancing tumor portions on first MRI < 48 hours postsurgery.

^bPartial resection, resection of < 95% of the preoperatively defined contrast-enhancing tumor portions on first MRI < 48 hours postsurgery.

^cPopulation A, seizure-free patients without AED prophylaxis; Population B, seizure-free with AED prophylaxis.

Abbreviations: LGG, low-grade glioma; HGG, high-grade glioma.