Mean ( SD ) POS scores at 4weeks were -5.7 ( 7.5 ) fast-track vs -0.4 ( 8.0 ) control , ( mean change difference between the two arms was -5.3 ( 95 % CI -9.8 to -0.7 ) independent t test p = 0.02 ) ; effect size ( 95 % CI ) -0.7 ( -1.2 to -0.1 ) .