Variables PDPH COR (95% CI) AOR (95% CI) P-value Yes No Sex Male 4 21 0.23(0.074, 0.731) 0.2(0.058, 0.67)  0.009 Female 41 50 1 1 Spinal needles Large needles* 40 49 3.6(1.25, 10.34) 5.3(1.66, 16.93) 0.005 Small needles** 5 22 1 1 Attempt Single 17 47 0.31(0.14, 0.67) 0.22(0.09, 0.54) 0.001 Multiple 28 24 1 1

Table 4: Factors associated with PDPH of patients who had SA in GUH, February 25-April 10, 2013. *needle sizes larger than 24 G; **needle sizes<24 G.