Table 3 Multivariable analysis (backward stepwise selection, p < 0.01 for staying in model)

Systolic blood pressure (per mmHg)

1.015 (1.007,1.022)

0.0001

Body temperature (per degree Celsius)

0.56 (0.38,0.82)

0.003

Rotary vertigo

0.32 (0.18,6.59)

0.0002

Sudden onset

0.35 (0.21,0.57)

< 0.0001

Nausea, vomiting

2.10 (1.29,3.43)

0.003

Sudden onset headache

8.54 (3.71,19.67)

< 0.0001

History of head trauma

4.13 (2.17,7.86)

< 0.0001

Treatment with anticoagulants

2.36 (1.39,3.99)

0.001