RT Journal Article SR Electronic T1 Forced expiratory volume in one second: why dichotomise? JF British Journal of Industrial Medicine JO Br J Ind Med FD BMJ Publishing Group Ltd SP 445 OP 447 DO 10.1136/oem.49.6.445 VO 49 IS 6 A1 Vestbo, J A1 Knudsen, K M A1 Rasmussen, F V YR 1992 UL http://oem.bmj.com/content/49/6/445.abstract AB