Combination group patients experienced a mean reduction of -3.1 ( 95 % CI , -3.8 to -2.3 ) in average arm pain at 1 month versus -1.8 ( CI , -2.5 to -1.2 ) in the conservative group and -2.0 ( CI , -2.7 to -1.3 ) in ESI patients ( P = 0.035 ) .