RT Journal Article SR Electronic T1 Assessing the validity of surrogate endpoints in the context of a controversy about the measurement of effectiveness of hepatitis C virus treatment JF BMJ Evidence-Based Medicine JO BMJ EBM FD BMJ Publishing Group Ltd SP 50 OP 53 DO 10.1136/bmjebm-2017-110852 VO 23 IS 2 A1 Claudia C Dobler A1 Rebecca L Morgan A1 Yngve Falck-Ytter A1 Victor M Montori A1 M Hassan Murad YR 2018 UL http://ebm.bmj.com/content/23/2/50.abstract AB