PT - JOURNAL ARTICLE AU - J A Deddens AU - M R Petersen TI - Approaches for estimating prevalence ratios AID - 10.1136/oem.2007.034777 DP - 2008 Jul 01 TA - Occupational and Environmental Medicine PG - 501--506 VI - 65 IP - 7 4099 - http://oem.bmj.com/content/65/7/501.short 4100 - http://oem.bmj.com/content/65/7/501.full SO - Occup Environ Med2008 Jul 01; 65