Table 4. Univariate and multivariate Cox models on time to change of first AED for adverse Effects.

Variable	Univariate	Multivariate 1	Multivariate 2
Sex (Men vs. Women)	0.63 (0.41–0.98)	0.63 (0.40–0.99)
Age (≥52 vs. <52)	0.84 (0.54–1.30)
Histology
Low grade gliomas vs. meningiomas	0.96 (0.51–1.84)
GBM/High grade gliomas vs. meningiomas	0.80 (0.47–1.37)
Metastases vs. meningiomas	0.42 (0.47–1.37)
Chemotherapy (Yes vs. No)	1.56 (1.01–2.41)
KPS (>80 vs.≤80)	1.41 (0.88–2.26)
Interval from first seizure to first AED	0.99 (0.99–1.00)
Center volume (≥20 patients vs. <20 patients)	0.65 (0.79–3.44)	2.81 (1.02–7.72)	2.96 (1.08–8.13)
First AED
Levetiracetam vs. carbamazepine	0.35 (0.16–0.78)	0.31 (0.14–0.71)
Oxcarbazepine vs. carbamazepine	0.64 (0.29–1.39)	0.64 (0.29–1.42)
Phenobarbital vs. carbamazepine	1.45 (0.78–2.68)	1.39 (0.73–2.63)
Phenytoin vs. carbamazepine	1.74 (0.67–4.49)	1.40 (0.46–4.26)
Topiramate vs. carbamazepine	Not evaluated	Not evaluated
Valproate vs. carbamazepine	0.69 (0.34–2.05)	0.77 (0.31–1.93)
First AED
Inducers vs. non-inducers	3.02 (1.83–4.98)		3.05 (1.83–5.07)
Valproate vs. non-inducers	1.92 (0.82–4.50)		2.00 (0.85–4.70)

AED = Antiepileptic drug; GBM = Glioblastoma multiforme; KPS = Karnovsky performance status.

Multivariate 1: Model with First AED not grouped; Multivariate 2: model with grouped First AED.