Table 3

Final multivariable stepwise logistic regression model using multiple imputation for missing information for factors associated with early neuroimaging

CT within 6 hours of headache onsetCT within 2 hours of hospital arrival
FactorsOR (95% CI)p ValueOR (95% CI)p Value
SAH1.68 (1.04 to 2.71)0.0331.42 (1.07 to 1.88)0.014
Onset during exertion2.14 (1.35 to 3.39)0.0011.52 (1.21 to 1.92)<0.001
Transfer from another hospital0.40 (0.26 to 0.59)<0.0014.72 (3.61 to 6.17)<0.001
Triage acuity
 High acuity vs low acuity3.11 (1.94 to 4.98)<0.0012.76 (2.07 to 3.68)<0.001
 Medium acuity vs low acuity1.76 (1.39 to 2.23)<0.0011.66 (1.44 to 1.92)<0.001
Arrival by ambulance1.39 (1.02 to 1.88)0.032
Worst headache of life1.33 (1.07 to 1.65)0.009
Prehospital delay (vs time >46, hours)
 time ≤31.90 (1.55 to 2.33)<0.001
 3< time ≤91.53 (1.34 to 1.76)<0.001
 9< time ≤461.23 (1.16 to 1.33)<0.001
  • Blank cells correspond to that factor having been removed from the model during stepwise selection due to p>0.05.

  • SAH, subarachnoid haemorrhage.