RT Journal Article SR Electronic T1 The yield of disease obtained at screening a middle aged population. JF British Journal of Preventive & Social Medicine JO Br J Prev Soc Med FD BMJ Publishing Group Ltd SP 54 OP 55 DO 10.1136/jech.26.1.54-b VO 26 IS 1 A1 H Trevelyan YR 1972 UL http://jech.bmj.com/content/26/1/54.3.abstract AB