Adjusted annualised relapse rates were 0397 ( 95 % CI 0328-0481 ) in the placebo group versus 0256 ( 0206-0318 ) in the every 2 weeks group and 0288 ( 0234-0355 ) in the every 4 weeks group ( rate ratio for every 2 weeks group 0644 , 95 % CI 0500-0831 , p = 00007 ; rate ratio for the every 4 weeks group 0725 , 95 % CI 0565-0930 , p = 00114 ) .