RT Journal Article SR Electronic T1 The Journal of Epidemiology and Community Health e-volution JF Journal of Epidemiology and Community Health JO J Epidemiol Community Health FD BMJ Publishing Group Ltd SP 241 OP 241 DO 10.1136/jech.54.4.241 VO 54 IS 4 A1 MARTA MARTIN-LLAGUNO A1 CARLOS ALVAREZ-DARDET YR 2000 UL http://jech.bmj.com/content/54/4/241.abstract AB