00398nas a2200157   4500000000100000008004100001100001400042700001600056700001500072700001400087700001300101245009700114300001500211490000800226050000600234       2008                            d1 aMacedo L.1 aHerbert Rob1 aMcAuley J.1 aKamper S.1 aMaher C.00aImperfect placebos are common in low back pain trials. A systematic review of the literature  a889-904.  0 v17   aY