Change in score from baseline to 48 weeks was more strongly associated with survival for the VACS Index than the Restricted Index with respective hazard ratios of 0.26 ( 95 % CI 0.14-0 .49 ) and 0.39 ( 95 % CI 0.22-0 .70 ) among the 25 % most improved scores , and 2.08 ( 95 % CI 1.27-3 .38 ) and 1.51 ( 95 % CI 0.90-2 .53 ) for the 25 % least improved scores .