Danish patients received higher doses than Icelandic patients at baseline [ median 3.1 ( interquartile range 3.0-3 .8 ) vs 2.3 ( 2.1-2 .9 ) mg/kg , P < 0.05 ] and after 12 months [ 3.3 ( 3.0-4 .5 ) vs 2.9 ( 2.2-3 .5 ) mg/kg , P < 0.0001 ] .