However , in a multivariable model , overall center volume and radial center volume were independently associated with the primary outcome but not femoral center volume ( overall percutaneous coronary intervention volume HR : 0.92 , 95 % CI : 0.88 to 0.96 ; radial volume HR : 0.88 , 95 % CI : 0.80 to 0.97 ; and femoral volume HR : 1.00 , 95 % CI : 0.94 to 1.07 ; p = 0.98 ) .