Variable

Univariate analysis

Multivariate analysis

P value

P value

Odd ratio

Confidence interval 95%

Age

0.038*

0.2

1.04

0.98 - 1.12

Neck width

continuous

Categorical (>4 mm)

0.01*

0.005*

0.65

1.4

0.32 - 7.65

Size of dome

continuous

Categorical (>10 mm)

0.008*

0.0.49

0.28

1.68

0.67 - 4.85

WFNS grade 4 - 5

0.0001*

0.01*

124

1.9 - 130

Modified Fisher grade 4

0.0004*

0.27

2.35

0.63 - 16.3