The differences ( etoricoxib vs celecoxib ) in least square ( LS ) mean change ( 95 % CI ) for WOMAC Pain , WOMAC Physical Function , and PGAD were -1.63 mm ( -5.37 , 2.10 ) , -1.32 mm ( -4.88 , 2.23 ) , and -1.09 mm ( -5.48 , 3.30 ) , respectively .