RT Journal Article SR Electronic T1 How to assess an article on economic evaluation. JF Sexually Transmitted Infections JO Sex Transm Infect FD BMJ Publishing Group Ltd SP 223 OP 227 DO 10.1136/sti.74.3.223 VO 74 IS 3 A1 M Sculpher A1 D Mercey YR 1998 UL http://sti.bmj.com/content/74/3/223.abstract AB