RT Journal Article SR Electronic T1 Faulty analysis or unsuitable data? JF Journal of Epidemiology and Community Health JO J Epidemiol Community Health FD BMJ Publishing Group Ltd SP 590 OP 590 VO 63 IS 7 A1 Bird, S M YR 2009 UL http://jech.bmj.com/content/63/7/590.1.abstract AB