RT Journal Article SR Electronic T1 Use of the prevalence ratio v the prevalence odds ratio as a measure of risk in cross sectional studies. JF Occupational and Environmental Medicine JO Occup Environ Med FD BMJ Publishing Group Ltd SP 574 OP 574 DO 10.1136/oem.51.8.574 VO 51 IS 8 A1 O Axelson A1 M Fredriksson A1 K Ekberg YR 1994 UL http://oem.bmj.com/content/51/8/574.abstract AB