RESULTS	Ambulatory patients had a later onset of PDPH than in-patients ( 24 h [ 0.5-72 ] vs. 2 h [ 0.2-96 ] , p = 0.0002 ) and the headache was more severe in these patients ( NRS 7 [ 2-10 ] vs. NRS 3 [ 1-8 ] , p = 0.0009 ) .\